diff --git a/.cursor-plugin/plugin.json b/.cursor-plugin/plugin.json index 14ddda8..f9c10fa 100644 --- a/.cursor-plugin/plugin.json +++ b/.cursor-plugin/plugin.json @@ -138,6 +138,8 @@ "examples/wave-displace" ], "showcase": [ - "showcase/shipping-crate" + "showcase/shipping-crate", + "showcase/stone-well", + "showcase/wooden-barrel" ] } diff --git a/AGENTS.md b/AGENTS.md index 12681d4..dec8a32 100644 --- a/AGENTS.md +++ b/AGENTS.md @@ -21,7 +21,7 @@ classifies it as a `cursor-plugin`. This is content the AI loads when the user asks Blender questions or works on Blender add-ons in Cursor or Claude Code. The content base is 16 skills, 9 rules, 3 templates, 27 snippets, 59 -examples, and 1 showcase piece (counts are CI-enforced against README.md +examples, and 3 showcase pieces (counts are CI-enforced against README.md and the manifest). The full inventory tables and per-item purposes live in `CLAUDE.md`. Example anatomy and authoring rules: copy `examples/bmesh-gear/`; showcase conventions: `showcase/README.md`. The render look is specified diff --git a/CLAUDE.md b/CLAUDE.md index 0f6e49b..32b449f 100644 --- a/CLAUDE.md +++ b/CLAUDE.md @@ -22,7 +22,7 @@ rules/.mdc - Anti-pattern rules, 9 total templates// - Starter projects, 3 total snippets/.py - Standalone code patterns, 27 total examples// - Runnable smoke-gated examples, 59 total (+ gallery.json) -showcase// - Budget-conformance props, 1 piece (sibling of examples/; see showcase/README.md) +showcase// - Budget-conformance props, 3 pieces (sibling of examples/; see showcase/README.md) scripts/build_gallery.py - Regenerates docs/gallery/ from examples/gallery.json + showcase/gallery.json scripts/site/ - Vendored landing-page build (Jinja2) docs/gallery/ - Committed generated gallery pages + hero renders diff --git a/README.md b/README.md index 1fe1fbf..4909166 100644 --- a/README.md +++ b/README.md @@ -18,7 +18,7 @@

- 16 skills  •  9 rules  •  3 templates  •  27 snippets  •  59 examples  •  1 showcase piece + 16 skills  •  9 rules  •  3 templates  •  27 snippets  •  59 examples  •  3 showcase pieces

@@ -37,7 +37,7 @@ ## Overview -This repository ships **16 skills, 9 rules, 3 templates, 27 snippets, 59 examples, and 1 showcase piece** for Blender Python development targeting Blender 5.2 LTS (current stable) with Blender 4.5 LTS fallback support. Blender 5.1 is prior stable. +This repository ships **16 skills, 9 rules, 3 templates, 27 snippets, 59 examples, and 3 showcase pieces** for Blender Python development targeting Blender 5.2 LTS (current stable) with Blender 4.5 LTS fallback support. Blender 5.1 is prior stable. The content is consumed by AI coding agents (Cursor, Claude Code, any MCP-capable client) when working on Blender add-ons, geometry nodes scripts, batch pipelines, or animation tooling. There is no build step. Edit the markdown and Python files directly. @@ -76,8 +76,14 @@ blender --background --python examples/bmesh-gear/bmesh_gear.py -- Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](showcase/README.md). Shipping crate: a wooden slat crate with iron corner brackets on a dark studio floor, warm wedge on the back wall +Stone well: a round brick well with a shingled pyramid roof on posts, rope and bucket, on a dark studio floor +Wooden barrel: a staved barrel with iron hoops on a dark studio floor, warm wedge on the back wall -First piece: [`shipping-crate`](showcase/shipping-crate/) — procedural crate through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets. Falsifier `--skip-decimate` exits 9. +[`shipping-crate`](showcase/shipping-crate/) — procedural crate through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets. Falsifier `--skip-decimate` exits 9. + +[`stone-well`](showcase/stone-well/) — procedural round stone well, shingled roof, windlass, rope and bucket through the same pipeline. Falsifier `--skip-decimate` exits 9. + +[`wooden-barrel`](showcase/wooden-barrel/) — procedural staved barrel with iron hoops through the same pipeline. Falsifier `--skip-decimate` exits 9. ## Examples diff --git a/ROADMAP.md b/ROADMAP.md index 4abb8bc..46409b8 100644 --- a/ROADMAP.md +++ b/ROADMAP.md @@ -107,6 +107,8 @@ Provider-agnostic GLB-in / engine-ready-out. This repo does not generate meshes. Not committed; target list for the next content version. (v0.3.0 shipped the smoke-gated `examples/` track.) - ~~Showcase sibling tree + shipping-crate pilot~~ **SHIPPED** as `showcase/shipping-crate/` — budget-conformance crate composing bake, LOD, collider, Unity glTF; `--skip-decimate` exits 9 on the LOD1 ratio band; DECIMATE COLLAPSE ratios diverge on 5.2 vs 4.5/5.1 +- ~~Round stone well showcase~~ **SHIPPED** as `showcase/stone-well/` — running-bond brick well, shingled pyramid roof, windlass/rope/bucket; `--skip-decimate` exits 9 on the LOD1 ratio band +- ~~Wooden barrel showcase~~ **SHIPPED** as `showcase/wooden-barrel/` — bulged staves, four iron hoops, lid heads; `--skip-decimate` exits 9 on the LOD1 ratio band - Procedural terrain or landscape showcase using Geometry Nodes scatter - Hero prop with a more complex silhouette (lantern or treasure chest) as a second showcase piece - Small modular kit showcase on recognizable geometry (`modular-kit-snap` contract) diff --git a/docs/gallery/assets/stone-well-hero.webp b/docs/gallery/assets/stone-well-hero.webp new file mode 100644 index 0000000..c043ede Binary files /dev/null and b/docs/gallery/assets/stone-well-hero.webp differ diff --git a/docs/gallery/assets/wooden-barrel-hero.webp b/docs/gallery/assets/wooden-barrel-hero.webp new file mode 100644 index 0000000..15b1521 Binary files /dev/null and b/docs/gallery/assets/wooden-barrel-hero.webp differ diff --git a/docs/gallery/index.html b/docs/gallery/index.html index 59daff5..98d5568 100644 --- a/docs/gallery/index.html +++ b/docs/gallery/index.html @@ -272,7 +272,7 @@

Examples Gallery

autocomplete="off" spellcheck="false" aria-label="Search examples" /> - 52 examples + 54 examples
@@ -896,6 +896,28 @@

shipping-crate

View example
+
+ + stone-well — A procedural stone well through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract. + +
+

stone-well

+

A procedural stone well through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.

+

witnesses Recomputed: 8388 tris, three materials, UVs in 0..1 with zero AABB overlap, outer AABB 1.640×1.640×1.688 m, LOD ratios in band, convex collider 230 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.

+ View example +
+
+
+ + wooden-barrel — A procedural staved barrel through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract. + +
+

wooden-barrel

+

A procedural staved barrel through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.

+

witnesses Recomputed: 4312 tris, two materials with 88 metal hoop faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.719×0.719×0.880 m, LOD ratios in band, convex collider 372 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.

+ View example +
+
diff --git a/docs/gallery/stone-well/index.html b/docs/gallery/stone-well/index.html new file mode 100644 index 0000000..72ece19 --- /dev/null +++ b/docs/gallery/stone-well/index.html @@ -0,0 +1,1145 @@ + + + + + + stone-well — Examples — Blender Developer Tools + + + + + + + + + + + + + + + + + +
+ Examples Gallery +
+ GitHub +
+
+
+

stone-well

+

A procedural stone well through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.

+
+
+ +

Rendered headless by the example itself — click to zoom.

+
witnesses Recomputed: 8388 tris, three materials, UVs in 0..1 with zero AABB overlap, outer AABB 1.640×1.640×1.688 m, LOD ratios in band, convex collider 230 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.
+
+ 
blender --background --python showcase/stone-well/stone_well.py --
+ +
+
+

A showcase piece, not an example. Procedural round stone well (running-bond bricks, curb, four posts, shingled pyramid roof, windlass, rope, bucket) then the shipped pipeline: unique-cell UVs, Cycles high-to-low normal bake, LOD chain, convex collider, Unity glTF export.

+

It asserts budget conformance of the generated result. It does not witness an API contract. "It rendered without error" is not a check.

+

Composes skills mesh-editing-and-bmesh, bake-high-to-low, depsgraph-and-evaluated-data, engine-export-presets, and snippets bake_normal_high_to_low.py, setup_bake_target_image.py, lod_chain.py / decimate_to_budget.py, convex_hull_collider.py, export_preset_unity.py (helpers copied, not imported as a package).

+

Budgets

+

Declared as named constants; every gate recomputes from the mesh, materials, UVs, evaluated LOD, collider, or export file.

+

| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) | | --- | --- | --- | | Base triangles | 8280–8500 | 8388 / 8388 / 8388 | | LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | | LOD2 ratio | 0.10–0.35 of base | 0.2198 / 0.2198 / 0.2198 | | Materials | exactly 3 distinct | 3 | | UVs | in 0..1, AABB overlap ≤ 1e-5 | in range, overlap 0 | | Outer AABB | (1.640, 1.640, 1.688) m ± 0.01 | (1.6400, 1.6400, 1.6882), zmin 0 | | Collider tris | ≤ 260 | 230 | | Export | written, size > 0 | 601028 / 601092 / 601372 bytes |

+

DECIMATE COLLAPSE triangle counts are not guaranteed identical across series — the gate is a ratio band, not an exact count. This mesh happened to match on 4.5.11 / 5.1.2 / 5.2.1. Bake pixels are stochastic; the gate is has_data plus operator FINISHED, not byte-identity. Construction uses no RNG. glTF byte size differs by a few hundred bytes across series.

+

--skip-decimate skips the LOD DECIMATE stage so LOD1 ratio is 1.0 and exit 9 fires. That is the named budget the falsifier violates.

+

Run

+
blender --background --python stone_well.py --
+blender --background --python stone_well.py -- --skip-decimate
+blender --background --python stone_well.py -- --output well.png
+

Smoke does not pass --output or --skip-decimate.

+

Exit codes

+

File-local. 9 is a valid check code. 10 is reserved for gallery_framing.check_framing on the --output path.

+

| Code | Meaning | | --- | --- | | 0 | Success | | 1 | Uncaught exception (FATAL wrapper) | | 2 | argparse / usage | | 3 | Mesh did not build / no UV layer | | 4 | Base triangle count outside range | | 5 | Material count ≠ 3 distinct slots | | 6 | UVs outside 0..1 | | 7 | UV AABB overlap above tolerance | | 8 | World AABB off declared outer size | | 9 | LOD ratio band (--skip-decimate lands here) | | 10 | Framing gate (render path only) | | 11 | Collider triangle count above ceiling | | 12 | Bake did not finish or image has no data | | 13 | Export file missing or empty | | 14 | --output produced no file |

+
+
+

Source

+
+ showcase/stone-well/stone_well.py + View on GitHub → +
+ 
"""Game-ready stone well — a showcase piece, not an example.
+
+Asserts budget conformance of a procedural well after composing shipped
+pipeline pieces: bmesh construction, UVs, three materials, high-to-low
+normal bake, LOD chain, convex collider, Unity glTF export.
+
+Budgets are declared below and recomputed from the generated result.
+They are not API-contract witnesses. ``--skip-decimate`` skips the LOD
+DECIMATE stage so the LOD-ratio budget fails.
+
+No RNG. Construction is closed-form. DECIMATE COLLAPSE triangle counts
+are not byte-identical across Blender versions — the LOD gate is a
+ratio band, not an exact count.
+
+    blender --background --python stone_well.py --
+    blender --background --python stone_well.py -- --skip-decimate
+    blender --background --python stone_well.py -- --output well.png
+"""
+import argparse
+import math
+import os
+import sys
+import tempfile
+import traceback
+
+import bmesh
+import bpy
+from mathutils import Euler, Vector
+
+# Showcase lives at repo-root/showcase/, not under examples/. The framing
+# helper is the repo's only shared import and lives next to the examples;
+# resolve the repo root so we do not move gallery_framing.py.
+_REPO = os.path.abspath(
+    os.path.join(os.path.dirname(os.path.abspath(__file__)), os.pardir, os.pardir)
+)
+sys.path.insert(0, os.path.join(_REPO, "examples"))
+sys.dont_write_bytecode = True
+import gallery_framing  # noqa: E402
+
+# Closed-form construction. OUTER_SIZE is the AABB of eaves + peak, compared
+# against the measured world bbox — not assigned onto the mesh.
+N_AROUND = 12
+N_ROWS = 5
+R_INNER = 0.40
+STONE_D = 0.14
+R_OUTER = R_INNER + STONE_D
+R_MID = (R_INNER + R_OUTER) / 2.0
+WALL_H = 0.72
+STONE_H = WALL_H / N_ROWS
+CURB_H = 0.065
+CURB_OUT = 0.045
+POST_S = 0.068
+POST_R = 0.55
+POST_H = 0.58
+POST_BOTTOM = WALL_H + CURB_H
+POST_TOP = POST_BOTTOM + POST_H
+EAVE_OVERHANG = 0.22
+EAVE_HALF = POST_R + POST_S / 2.0 + EAVE_OVERHANG
+EAVE_Z = POST_TOP - 0.02
+ROOF_RISE = 0.34
+PEAK_Z = EAVE_Z + ROOF_RISE
+SHINGLE_T = 0.016
+WINDLASS_R = 0.045
+BUCKET_R = 0.10
+BUCKET_H = 0.14
+BUCKET_Z = 0.68
+ROPE_R = 0.016
+BBOX_TOL = 0.01
+# Fitted to the generated AABB after locking geometry. Recomputed from bound_box.
+OUTER_SIZE = (1.640, 1.640, 1.688)
+
+# Measured after locking geometry. DECIMATE COLLAPSE ratios diverge across
+# series — bands, not exact counts. Tightened after the first 4.5/5.1/5.2 run.
+BASE_TRIS_MIN = 8280
+BASE_TRIS_MAX = 8500
+LOD1_RATIO_MIN = 0.32
+LOD1_RATIO_MAX = 0.62
+LOD2_RATIO_MIN = 0.10
+LOD2_RATIO_MAX = 0.35
+LOD1_TARGET = 0.50
+LOD2_TARGET = 0.22
+MATERIAL_COUNT = 3
+UV_EPS = 1e-4
+UV_OVERLAP_MAX = 1e-5
+COLLIDER_TRIS_MAX = 260
+BAKE_RES = 256
+CAGE_EXTRUSION = 0.06
+
+STONE_IDX = 0
+WOOD_IDX = 1
+METAL_IDX = 2
+
+
+def eevee_engine_id():
+    return "BLENDER_EEVEE" if bpy.app.version >= (5, 0, 0) else "BLENDER_EEVEE_NEXT"
+
+
+def fail(msg, code):
+    print(f"ERROR: {msg}", file=sys.stderr)
+    return code
+
+
+def triangle_count(mesh):
+    mesh.calc_loop_triangles()
+    return len(mesh.loop_triangles)
+
+
+def evaluated_triangle_count(obj):
+    # Duplicated from snippets/lod_chain.py / decimate_to_budget.py (not a package).
+    depsgraph = bpy.context.evaluated_depsgraph_get()
+    eval_obj = obj.evaluated_get(depsgraph)
+    eval_mesh = eval_obj.to_mesh()
+    try:
+        eval_mesh.calc_loop_triangles()
+        return len(eval_mesh.loop_triangles)
+    finally:
+        eval_obj.to_mesh_clear()
+
+
+def add_box(bm, loc, scale, mat_idx, euler=(0.0, 0.0, 0.0)):
+    geo = bmesh.ops.create_cube(bm, size=1.0)
+    verts = geo["verts"]
+    rot = Euler(euler).to_matrix()
+    origin = Vector(loc)
+    for v in verts:
+        p = Vector((v.co.x * scale[0], v.co.y * scale[1], v.co.z * scale[2]))
+        v.co = rot @ p + origin
+    faces = {f for v in verts for f in v.link_faces}
+    for f in faces:
+        f.material_index = mat_idx
+    return verts
+
+
+def add_cone(bm, loc, radius1, radius2, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)):
+    geo = bmesh.ops.create_cone(
+        bm,
+        cap_ends=True,
+        cap_tris=False,
+        segments=segments,
+        radius1=radius1,
+        radius2=radius2,
+        depth=depth,
+    )
+    verts = geo["verts"]
+    rot = Euler(euler).to_matrix()
+    origin = Vector(loc)
+    for v in verts:
+        v.co = rot @ v.co + origin
+    faces = {f for v in verts for f in v.link_faces}
+    for f in faces:
+        f.material_index = mat_idx
+    return verts
+
+
+def add_cylinder(bm, loc, radius, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)):
+    return add_cone(bm, loc, radius, radius, depth, segments, mat_idx, euler=euler)
+
+
+def pack_uvs(bm, margin=0.08):
+    uv = bm.loops.layers.uv.new("UVMap")
+    faces = list(bm.faces)
+    n = len(faces)
+    cols = max(1, math.ceil(math.sqrt(n)))
+    rows = max(1, math.ceil(n / cols))
+    cell_w = 1.0 / cols
+    cell_h = 1.0 / rows
+    pad_u = margin * cell_w * 0.5
+    pad_v = margin * cell_h * 0.5
+    usable_w = cell_w - 2.0 * pad_u
+    usable_h = cell_h - 2.0 * pad_v
+    for i, face in enumerate(faces):
+        col = i % cols
+        row = i // cols
+        nrm = face.normal
+        ax = abs(nrm.x)
+        ay = abs(nrm.y)
+        az = abs(nrm.z)
+        coords = []
+        for loop in face.loops:
+            co = loop.vert.co
+            if az >= ax and az >= ay:
+                coords.append((co.x, co.y))
+            elif ax >= ay:
+                coords.append((co.y, co.z))
+            else:
+                coords.append((co.x, co.z))
+        xs = [c[0] for c in coords]
+        ys = [c[1] for c in coords]
+        minx, maxx = min(xs), max(xs)
+        miny, maxy = min(ys), max(ys)
+        dx = max(maxx - minx, 1e-8)
+        dy = max(maxy - miny, 1e-8)
+        origin_u = col * cell_w + pad_u
+        origin_v = row * cell_h + pad_v
+        for loop, (x, y) in zip(face.loops, coords):
+            loop[uv].uv = (
+                origin_u + (x - minx) / dx * usable_w,
+                origin_v + (y - miny) / dy * usable_h,
+            )
+
+
+def build_well_mesh(name, bevel_offset, bevel_segments):
+    bm = bmesh.new()
+    stone_verts = []
+    try:
+        stone_w = 2.0 * R_MID * math.tan(math.pi / N_AROUND) * 0.88
+        actual_h = STONE_H * 0.90
+        for row in range(N_ROWS):
+            z = actual_h / 2.0 + row * STONE_H
+            rot_off = (row % 2) * (math.pi / N_AROUND)
+            for i in range(N_AROUND):
+                ang = 2.0 * math.pi * i / N_AROUND + rot_off
+                loc = (R_MID * math.cos(ang), R_MID * math.sin(ang), z)
+                stone_verts.extend(
+                    add_box(
+                        bm,
+                        loc,
+                        (STONE_D, stone_w, actual_h),
+                        STONE_IDX,
+                        euler=(0.0, 0.0, ang),
+                    )
+                )
+
+        curb_r = R_OUTER + CURB_OUT / 2.0
+        curb_w = 2.0 * curb_r * math.tan(math.pi / N_AROUND) * 0.90
+        curb_z = WALL_H + CURB_H / 2.0
+        for i in range(N_AROUND):
+            ang = 2.0 * math.pi * i / N_AROUND
+            loc = (curb_r * math.cos(ang), curb_r * math.sin(ang), curb_z)
+            stone_verts.extend(
+                add_box(
+                    bm,
+                    loc,
+                    (STONE_D + CURB_OUT, curb_w, CURB_H),
+                    STONE_IDX,
+                    euler=(0.0, 0.0, ang),
+                )
+            )
+
+        if bevel_offset > 0.0:
+            edges = list({e for v in stone_verts for e in v.link_edges})
+            bmesh.ops.bevel(
+                bm,
+                geom=edges,
+                offset=bevel_offset,
+                segments=bevel_segments,
+                profile=0.5,
+                affect="EDGES",
+                clamp_overlap=True,
+            )
+
+        post_angles = (0.0, math.pi / 2.0, math.pi, 3.0 * math.pi / 2.0)
+        for ang in post_angles:
+            loc = (
+                POST_R * math.cos(ang),
+                POST_R * math.sin(ang),
+                POST_BOTTOM + POST_H / 2.0,
+            )
+            add_box(bm, loc, (POST_S, POST_S, POST_H), WOOD_IDX)
+
+        beam_z = POST_TOP - 0.05
+        add_box(
+            bm,
+            (0.0, 0.0, beam_z),
+            (POST_R * 2.0 - POST_S, POST_S * 0.85, POST_S * 0.85),
+            WOOD_IDX,
+        )
+        add_cylinder(
+            bm,
+            (0.0, 0.0, beam_z),
+            WINDLASS_R,
+            POST_R * 2.0 - POST_S * 1.4,
+            12,
+            WOOD_IDX,
+            euler=(0.0, math.pi / 2.0, 0.0),
+        )
+        add_box(
+            bm,
+            (POST_R - POST_S * 0.2, 0.0, beam_z),
+            (0.018, 0.12, 0.018),
+            METAL_IDX,
+            euler=(0.0, 0.0, math.radians(25.0)),
+        )
+
+        pitch = math.atan(ROOF_RISE / EAVE_HALF)
+        r_base = EAVE_HALF * math.sqrt(2.0)
+        add_cone(
+            bm,
+            (0.0, 0.0, (EAVE_Z + PEAK_Z) / 2.0),
+            r_base,
+            0.04,
+            ROOF_RISE,
+            4,
+            WOOD_IDX,
+            euler=(0.0, 0.0, math.pi / 4.0),
+        )
+        nrm_local = Vector((0.0, ROOF_RISE, EAVE_HALF)).normalized()
+
+        def add_course(yaw, t0, t1):
+            rot = Euler((0.0, 0.0, yaw)).to_matrix()
+            nrm = rot @ nrm_local
+
+            def pt(t, s):
+                w = EAVE_HALF * t
+                y = t * EAVE_HALF
+                z = PEAK_Z - t * ROOF_RISE
+                return rot @ Vector((s * w, y, z))
+
+            inner = SHINGLE_T * 0.12
+            outer = SHINGLE_T * 1.05
+            corners = (
+                pt(t0, -1.0),
+                pt(t0, 1.0),
+                pt(t1, 1.0),
+                pt(t1, -1.0),
+            )
+            vs = [bm.verts.new(c + nrm * inner) for c in corners]
+            vs.extend(bm.verts.new(c + nrm * outer) for c in corners)
+            idx = (
+                (0, 1, 2, 3),
+                (4, 7, 6, 5),
+                (0, 4, 5, 1),
+                (1, 5, 6, 2),
+                (2, 6, 7, 3),
+                (3, 7, 4, 0),
+            )
+            for a, b, c, d in idx:
+                face = bm.faces.new((vs[a], vs[b], vs[c], vs[d]))
+                face.material_index = WOOD_IDX
+
+        n_rows = 5
+        for side in range(4):
+            yaw = side * (math.pi / 2.0)
+            for row in range(n_rows):
+                t0 = (row + 0.18) / n_rows
+                t1 = (row + 1.08) / n_rows
+                if t1 > 1.0:
+                    t1 = 1.0
+                add_course(yaw, t0, t1)
+        fascia_h = 0.045
+        fascia_t = 0.032
+        for side in range(4):
+            yaw = side * (math.pi / 2.0)
+            fx = EAVE_HALF * math.sin(yaw)
+            fy = EAVE_HALF * math.cos(yaw)
+            if side % 2 == 0:
+                add_box(
+                    bm,
+                    (0.0, fy, EAVE_Z - fascia_h / 2.0),
+                    (2.0 * EAVE_HALF + fascia_t, fascia_t, fascia_h),
+                    WOOD_IDX,
+                )
+            else:
+                add_box(
+                    bm,
+                    (fx, 0.0, EAVE_Z - fascia_h / 2.0),
+                    (fascia_t, 2.0 * EAVE_HALF + fascia_t, fascia_h),
+                    WOOD_IDX,
+                )
+
+        rope_top = beam_z - WINDLASS_R
+        rope_bot = BUCKET_Z + BUCKET_H / 2.0
+        rope_h = rope_top - rope_bot
+        add_cylinder(
+            bm,
+            (0.0, 0.0, (rope_top + rope_bot) / 2.0),
+            ROPE_R,
+            rope_h,
+            8,
+            WOOD_IDX,
+        )
+        add_cylinder(bm, (0.0, 0.0, BUCKET_Z), BUCKET_R, BUCKET_H, 12, WOOD_IDX)
+        for hz in (-BUCKET_H * 0.28, BUCKET_H * 0.28):
+            add_cylinder(
+                bm,
+                (0.0, 0.0, BUCKET_Z + hz),
+                BUCKET_R + 0.008,
+                0.018,
+                12,
+                METAL_IDX,
+            )
+        add_box(
+            bm,
+            (0.0, 0.0, BUCKET_Z + BUCKET_H / 2.0 + 0.04),
+            (BUCKET_R * 1.6, 0.014, 0.014),
+            METAL_IDX,
+        )
+        add_box(
+            bm,
+            (-BUCKET_R * 0.72, 0.0, BUCKET_Z + BUCKET_H / 2.0 + 0.02),
+            (0.014, 0.014, 0.05),
+            METAL_IDX,
+        )
+        add_box(
+            bm,
+            (BUCKET_R * 0.72, 0.0, BUCKET_Z + BUCKET_H / 2.0 + 0.02),
+            (0.014, 0.014, 0.05),
+            METAL_IDX,
+        )
+
+        pack_uvs(bm)
+        bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces))
+        for face in bm.faces:
+            face.smooth = True
+        for edge in bm.edges:
+            edge.smooth = True
+            if edge.is_manifold and len(edge.link_faces) == 2:
+                if edge.calc_face_angle() > math.radians(35.0):
+                    edge.smooth = False
+        me = bpy.data.meshes.new(name)
+        bm.to_mesh(me)
+        me.update()
+    finally:
+        bm.free()
+    obj = bpy.data.objects.new(name, me)
+    bpy.context.collection.objects.link(obj)
+    return obj
+
+
+def principled(name, color, metallic, roughness):
+    mat = bpy.data.materials.new(name)
+    mat.use_nodes = True
+    bsdf = mat.node_tree.nodes["Principled BSDF"]
+    bsdf.inputs["Base Color"].default_value = color
+    bsdf.inputs["Metallic"].default_value = metallic
+    bsdf.inputs["Roughness"].default_value = roughness
+    return mat
+
+
+def assign_slots(obj, stone, wood, metal):
+    obj.data.materials.clear()
+    obj.data.materials.append(stone)
+    obj.data.materials.append(wood)
+    obj.data.materials.append(metal)
+
+
+def world_bbox(obj):
+    corners = [obj.matrix_world @ Vector(c) for c in obj.bound_box]
+    xs = [c.x for c in corners]
+    ys = [c.y for c in corners]
+    zs = [c.z for c in corners]
+    return (min(xs), min(ys), min(zs), max(xs), max(ys), max(zs))
+
+
+def uv_stats(mesh):
+    uv = mesh.uv_layers.active
+    if uv is None:
+        return 0.0, 0.0, 1.0, 1.0, 0, 1.0
+    data = uv.data
+    us = [loop.uv[0] for loop in data]
+    vs = [loop.uv[1] for loop in data]
+    aabbs = []
+    for poly in mesh.polygons:
+        pu = [data[i].uv[0] for i in poly.loop_indices]
+        pv = [data[i].uv[1] for i in poly.loop_indices]
+        aabbs.append((min(pu), min(pv), max(pu), max(pv)))
+    overlap = 0.0
+    for i in range(len(aabbs)):
+        a = aabbs[i]
+        for j in range(i + 1, len(aabbs)):
+            b = aabbs[j]
+            x0 = max(a[0], b[0])
+            y0 = max(a[1], b[1])
+            x1 = min(a[2], b[2])
+            y1 = min(a[3], b[3])
+            overlap += max(0.0, x1 - x0) * max(0.0, y1 - y0)
+    return min(us), min(vs), max(us), max(vs), overlap, len(aabbs)
+
+
+def make_lod(obj, name, ratio, skip_decimate):
+    mesh = obj.data.copy()
+    lod = bpy.data.objects.new(name, mesh)
+    lod.matrix_world = obj.matrix_world.copy()
+    bpy.context.scene.collection.objects.link(lod)
+    if not skip_decimate and 0.0 < ratio < 1.0:
+        mod = lod.modifiers.new("DecimateBudget", "DECIMATE")
+        mod.decimate_type = "COLLAPSE"
+        mod.ratio = ratio
+    return lod
+
+
+def convex_hull_collider(obj, name):
+    # Duplicated from snippets/convex_hull_collider.py (not a package).
+    mesh = bpy.data.meshes.new(name)
+    bm = bmesh.new()
+    try:
+        bm.from_mesh(obj.data)
+        result = bmesh.ops.convex_hull(bm, input=list(bm.verts))
+        interior = result.get("geom_interior") or []
+        unused = result.get("geom_unused") or []
+        if interior:
+            bmesh.ops.delete(bm, geom=interior, context="VERTS")
+        if unused:
+            bmesh.ops.delete(bm, geom=unused, context="VERTS")
+        bm.to_mesh(mesh)
+        mesh.update()
+    finally:
+        bm.free()
+    collider = bpy.data.objects.new(name, mesh)
+    bpy.context.collection.objects.link(collider)
+    collider.matrix_world = obj.matrix_world.copy()
+    return collider
+
+
+def setup_bake_image(obj, target_mat, size=BAKE_RES):
+    # Adapted from snippets/setup_bake_target_image.py — do not replace slots.
+    if not obj.data.uv_layers:
+        return None, None
+    img = bpy.data.images.new("WellNrm", size, size, alpha=True, float_buffer=False)
+    img.colorspace_settings.name = "Non-Color"
+    nodes = target_mat.node_tree.nodes
+    tex = nodes.new("ShaderNodeTexImage")
+    tex.image = img
+    nodes.active = tex
+    tex.select = True
+    obj.active_material_index = STONE_IDX
+    return img, tex
+
+
+def bake_normal(high, low):
+    # Duplicated from snippets/bake_normal_high_to_low.py (not a package).
+    scene = bpy.context.scene
+    scene.render.engine = "CYCLES"
+    scene.cycles.device = "CPU"
+    scene.cycles.samples = 1
+    scene.cycles.use_denoising = False
+    for ob in bpy.context.view_layer.objects:
+        ob.select_set(False)
+    high.select_set(True)
+    low.select_set(True)
+    bpy.context.view_layer.objects.active = low
+    return bpy.ops.object.bake(
+        type="NORMAL",
+        use_selected_to_active=True,
+        cage_extrusion=CAGE_EXTRUSION,
+        use_cage=False,
+        normal_space="TANGENT",
+        margin=4,
+        margin_type="ADJACENT_FACES",
+        use_clear=True,
+        target="IMAGE_TEXTURES",
+    )
+
+
+def export_unity(path, objects):
+    # Duplicated from snippets/export_preset_unity.py (not a package).
+    for ob in bpy.context.view_layer.objects:
+        ob.select_set(False)
+    for ob in objects:
+        ob.select_set(True)
+    bpy.context.view_layer.objects.active = objects[0]
+    bpy.ops.export_scene.gltf(
+        filepath=path,
+        use_selection=True,
+        export_yup=True,
+        export_apply=True,
+        export_draco_mesh_compression_enable=False,
+        export_animations=False,
+    )
+
+
+def check(skip_decimate):
+    bpy.ops.wm.read_factory_settings(use_empty=True)
+    low = build_well_mesh("WellLow", bevel_offset=0.010, bevel_segments=2)
+    high = build_well_mesh("WellHigh", bevel_offset=0.010, bevel_segments=4)
+    stone = principled("WellStone", (0.40, 0.42, 0.46, 1.0), 0.0, 0.84)
+    wood = principled("WellWood", (0.48, 0.22, 0.07, 1.0), 0.0, 0.50)
+    metal = principled("WellMetal", (0.62, 0.58, 0.48, 1.0), 1.0, 0.25)
+    assign_slots(low, stone, wood, metal)
+    assign_slots(high, stone, wood, metal)
+
+    if low.data is None or len(low.data.polygons) < 6:
+        return fail("well mesh did not build", 3), None, None, None, None, None
+
+    base_tris = triangle_count(low.data)
+    mats = [s for s in low.data.materials if s is not None]
+    nmat = len(mats)
+    distinct_mats = len({id(s) for s in mats})
+    u0, v0, u1, v1, overlap, nfaces = uv_stats(low.data)
+    bb = world_bbox(low)
+    size_x = bb[3] - bb[0]
+    size_y = bb[4] - bb[1]
+    size_z = bb[5] - bb[2]
+
+    img, tex = setup_bake_image(low, stone)
+    if img is None:
+        return fail("well has no UV layer", 3), None, None, None, None, None
+    bake_result = bake_normal(high, low)
+
+    lod1 = make_lod(low, "WellLOD1", LOD1_TARGET, skip_decimate)
+    lod2 = make_lod(low, "WellLOD2", LOD2_TARGET, skip_decimate)
+    bpy.context.view_layer.update()
+    lod1_tris = evaluated_triangle_count(lod1)
+    lod2_tris = evaluated_triangle_count(lod2)
+    r1 = lod1_tris / base_tris if base_tris else 0.0
+    r2 = lod2_tris / base_tris if base_tris else 0.0
+
+    collider = convex_hull_collider(low, "WellCollider")
+    col_tris = triangle_count(collider.data)
+
+    export_path = os.path.join(
+        tempfile.gettempdir(),
+        f"bdt_stone_well_{os.getpid()}.glb",
+    )
+    if os.path.exists(export_path):
+        os.remove(export_path)
+    export_unity(export_path, [low, collider])
+    export_size = os.path.getsize(export_path) if os.path.isfile(export_path) else 0
+
+    print(
+        f"blender={tuple(bpy.app.version)} skip_decimate={skip_decimate}"
+    )
+    print(
+        f"measured base_tris={base_tris} lod1_tris={lod1_tris} "
+        f"lod2_tris={lod2_tris} r1={r1:.4f} r2={r2:.4f}"
+    )
+    print(
+        f"measured nmat={nmat} uv=({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f}) "
+        f"overlap={overlap:.6f} nfaces={nfaces}"
+    )
+    print(
+        f"measured bbox=({size_x:.4f},{size_y:.4f},{size_z:.4f}) "
+        f"outer={OUTER_SIZE} zmin={bb[2]:.4f}"
+    )
+    print(
+        f"measured collider_tris={col_tris} bake={bake_result} "
+        f"bake_has_data={img.has_data} export_bytes={export_size}"
+    )
+
+    if not (BASE_TRIS_MIN <= base_tris <= BASE_TRIS_MAX):
+        return fail(
+            f"base tris {base_tris} not in [{BASE_TRIS_MIN}, {BASE_TRIS_MAX}]",
+            4,
+        ), None, None, None, None, None
+    if nmat != MATERIAL_COUNT or distinct_mats != MATERIAL_COUNT:
+        return fail(
+            f"material slots {nmat} distinct {distinct_mats} != {MATERIAL_COUNT}",
+            5,
+        ), None, None, None, None, None
+    if u0 < -UV_EPS or v0 < -UV_EPS or u1 > 1.0 + UV_EPS or v1 > 1.0 + UV_EPS:
+        return fail(
+            f"UVs outside 0..1: ({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f})",
+            6,
+        ), None, None, None, None, None
+    if overlap > UV_OVERLAP_MAX:
+        return fail(
+            f"UV AABB overlap {overlap:.6f} > {UV_OVERLAP_MAX}",
+            7,
+        ), None, None, None, None, None
+    if (
+        abs(size_x - OUTER_SIZE[0]) > BBOX_TOL
+        or abs(size_y - OUTER_SIZE[1]) > BBOX_TOL
+        or abs(size_z - OUTER_SIZE[2]) > BBOX_TOL
+    ):
+        return fail(
+            f"bbox ({size_x:.4f},{size_y:.4f},{size_z:.4f}) "
+            f"off outer {OUTER_SIZE}",
+            8,
+        ), None, None, None, None, None
+    if not (LOD1_RATIO_MIN <= r1 <= LOD1_RATIO_MAX):
+        return fail(
+            f"LOD1 ratio {r1:.4f} not in [{LOD1_RATIO_MIN}, {LOD1_RATIO_MAX}] "
+            "(--skip-decimate is the designed fail)",
+            9,
+        ), None, None, None, None, None
+    if not (LOD2_RATIO_MIN <= r2 <= LOD2_RATIO_MAX):
+        return fail(
+            f"LOD2 ratio {r2:.4f} not in [{LOD2_RATIO_MIN}, {LOD2_RATIO_MAX}]",
+            9,
+        ), None, None, None, None, None
+    if col_tris > COLLIDER_TRIS_MAX:
+        return fail(
+            f"collider tris {col_tris} > {COLLIDER_TRIS_MAX}",
+            11,
+        ), None, None, None, None, None
+    if bake_result != {"FINISHED"} or not img.has_data:
+        return fail(
+            f"bake failed result={bake_result} has_data={img.has_data}",
+            12,
+        ), None, None, None, None, None
+    if export_size <= 0:
+        return fail("export file missing or empty", 13), None, None, None, None, None
+    return 0, low, high, stone, tex, collider
+
+
+def wire_normal(mat, tex):
+    nt = mat.node_tree
+    bsdf = nt.nodes["Principled BSDF"]
+    nrm = nt.nodes.new("ShaderNodeNormalMap")
+    nrm.inputs["Strength"].default_value = 1.0
+    nt.links.new(tex.outputs["Color"], nrm.inputs["Color"])
+    nt.links.new(nrm.outputs["Normal"], bsdf.inputs["Normal"])
+
+
+def render_still(low, stone, tex, path, engine):
+    scene = bpy.context.scene
+    wire_normal(stone, tex)
+    for ob in list(scene.objects):
+        if ob.type == "MESH" and ob != low:
+            ob.hide_render = True
+            ob.hide_viewport = True
+
+    low.rotation_euler.z = math.radians(-28.0)
+    low.rotation_euler.x = math.radians(2.0)
+
+    floor_me = bpy.data.meshes.new("Floor")
+    bm = bmesh.new()
+    try:
+        bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0)
+        bm.to_mesh(floor_me)
+    finally:
+        bm.free()
+    fmat = bpy.data.materials.new("Floor")
+    fmat.use_nodes = True
+    fb = fmat.node_tree.nodes["Principled BSDF"]
+    fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0)
+    fb.inputs["Roughness"].default_value = 0.7
+    floor_me.materials.append(fmat)
+    floor = bpy.data.objects.new("Floor", floor_me)
+    scene.collection.objects.link(floor)
+    wall = bpy.data.objects.new("Wall", floor_me.copy())
+    wall.location = (0.0, 8.5, 0.0)
+    wall.rotation_euler = (math.radians(90), 0.0, 0.0)
+    scene.collection.objects.link(wall)
+
+    world = bpy.data.worlds.new("World")
+    world.use_nodes = True
+    world.node_tree.nodes["Background"].inputs["Color"].default_value = (
+        0.02, 0.021, 0.025, 1.0,
+    )
+    scene.world = world
+
+    def light(name, loc, energy, size, col, rot):
+        ld = bpy.data.lights.new(name, "AREA")
+        ld.energy = energy
+        ld.size = size
+        ld.color = col
+        ob = bpy.data.objects.new(name, ld)
+        ob.location = loc
+        ob.rotation_euler = tuple(math.radians(a) for a in rot)
+        scene.collection.objects.link(ob)
+
+    light("Key", (-3.6, -5.0, 5.8), 680.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36))
+    light("Fill", (5.0, -3.6, 2.6), 48.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50))
+    light("Wedge", (2.4, 4.2, 4.1), 640.0, 5.5, (1.0, 0.70, 0.40), (-70, 0, 198))
+
+    cam_data = bpy.data.cameras.new("Cam")
+    cam_data.lens = 50.0
+    cam = bpy.data.objects.new("Cam", cam_data)
+    cam.location = (3.10, -4.45, 2.12)
+    scene.collection.objects.link(cam)
+    aim = bpy.data.objects.new("Aim", None)
+    aim.location = (0.0, 0.0, OUTER_SIZE[2] / 2.0 + 0.04)
+    scene.collection.objects.link(aim)
+    con = cam.constraints.new("TRACK_TO")
+    con.target = aim
+    con.track_axis = "TRACK_NEGATIVE_Z"
+    con.up_axis = "UP_Y"
+    scene.camera = cam
+
+    scene.render.engine = "CYCLES" if engine == "cycles" else eevee_engine_id()
+    if engine == "cycles":
+        scene.cycles.samples = 32
+        scene.cycles.device = "CPU"
+    else:
+        try:
+            scene.eevee.taa_render_samples = 64
+        except AttributeError:
+            pass
+    scene.render.resolution_x = 1280
+    scene.render.resolution_y = 720
+    scene.render.image_settings.file_format = (
+        "WEBP" if path.lower().endswith(".webp") else "PNG"
+    )
+    if path.lower().endswith(".webp"):
+        scene.render.image_settings.quality = 90
+    scene.render.filepath = path
+    scene.view_settings.view_transform = "Standard"
+
+    fcode = gallery_framing.check_framing(
+        scene, cam, hero=[low], elements=[low], stage=[floor, wall],
+    )
+    if fcode:
+        return fcode
+    bpy.ops.render.render(write_still=True)
+    if not (os.path.exists(path) and os.path.getsize(path) > 0):
+        return fail("render produced no file", 14)
+    return 0
+
+
+def main():
+    argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []
+    p = argparse.ArgumentParser()
+    p.add_argument("--output", default=None)
+    p.add_argument("--engine", default="eevee", choices=("eevee", "cycles"))
+    p.add_argument(
+        "--skip-decimate",
+        action="store_true",
+        help="falsification: skip the LOD DECIMATE stage",
+    )
+    args = p.parse_args(argv)
+
+    code, low, _high, stone, tex, _col = check(args.skip_decimate)
+    if code:
+        return code
+    if args.output:
+        rcode = render_still(low, stone, tex, os.path.abspath(args.output), args.engine)
+        if rcode:
+            return rcode
+        print(f"rendered still {args.output}")
+    print("stone-well OK")
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        sys.exit(main())
+    except Exception as e:
+        traceback.print_exc()
+        print(f"FATAL: {e}", file=sys.stderr)
+        sys.exit(1)
+
+
+
+ +
+
+ generated from examples/gallery.json + CC-BY-NC-ND-4.0 + exit 0 +
+
+ + + diff --git a/docs/gallery/wooden-barrel/index.html b/docs/gallery/wooden-barrel/index.html new file mode 100644 index 0000000..760bc56 --- /dev/null +++ b/docs/gallery/wooden-barrel/index.html @@ -0,0 +1,1009 @@ + + + + + + wooden-barrel — Examples — Blender Developer Tools + + + + + + + + + + + + + + + + + +
+ Examples Gallery +
+ GitHub +
+
+
+

wooden-barrel

+

A procedural staved barrel through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.

+
+
+ +

Rendered headless by the example itself — click to zoom.

+
witnesses Recomputed: 4312 tris, two materials with 88 metal hoop faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.719×0.719×0.880 m, LOD ratios in band, convex collider 372 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.
+
+ 
blender --background --python showcase/wooden-barrel/wooden_barrel.py --
+ +
+
+

A showcase piece, not an example. Procedural staved barrel (bulged staves, four iron hoops, top and bottom heads) then the shipped pipeline: unique-cell UVs, Cycles high-to-low normal bake, LOD chain, convex collider, Unity glTF export.

+

It asserts budget conformance of the generated result. It does not witness an API contract. "It rendered without error" is not a check.

+

Composes skills mesh-editing-and-bmesh, bake-high-to-low, depsgraph-and-evaluated-data, engine-export-presets, and snippets bake_normal_high_to_low.py, setup_bake_target_image.py, lod_chain.py / decimate_to_budget.py, convex_hull_collider.py, export_preset_unity.py (helpers copied, not imported as a package).

+

Budgets

+

Declared as named constants; every gate recomputes from the mesh, materials, UVs, evaluated LOD, collider, or export file.

+

| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) | | --- | --- | --- | | Base triangles | 4200–4450 | 4312 / 4312 / 4312 | | LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | | LOD2 ratio | 0.10–0.35 of base | 0.2199 / 0.2199 / 0.2199 | | Materials | exactly 2 distinct, ≥16 metal hoop faces | 2 slots, 88 hoop faces | | UVs | in 0..1, AABB overlap ≤ 1e-5 | in range, overlap 0 | | Outer AABB | (0.719, 0.719, 0.880) m ± 0.01 | (0.7194, 0.7194, 0.8800), zmin 0 | | Collider tris | ≤ 400 | 372 | | Export | written, size > 0 | 327564 / 327564 / 327556 bytes |

+

DECIMATE COLLAPSE triangle counts are not guaranteed identical across series — the gate is a ratio band, not an exact count. This mesh happened to match on 4.5.11 / 5.1.2 / 5.2.1. Bake pixels are stochastic; the gate is has_data plus operator FINISHED, not byte-identity. Construction uses no RNG. glTF byte size differs by a few bytes across series.

+

--skip-decimate skips the LOD DECIMATE stage so LOD1 ratio is 1.0 and exit 9 fires. That is the named budget the falsifier violates.

+

Run

+
blender --background --python wooden_barrel.py --
+blender --background --python wooden_barrel.py -- --skip-decimate
+blender --background --python wooden_barrel.py -- --output barrel.png
+

Smoke does not pass --output or --skip-decimate.

+

Exit codes

+

File-local. 9 is a valid check code. 10 is reserved for gallery_framing.check_framing on the --output path.

+

| Code | Meaning | | --- | --- | | 0 | Success | | 1 | Uncaught exception (FATAL wrapper) | | 2 | argparse / usage | | 3 | Mesh did not build / no UV layer | | 4 | Base triangle count outside range | | 5 | Material count ≠ 2 distinct slots, or hoop faces missing | | 6 | UVs outside 0..1 | | 7 | UV AABB overlap above tolerance | | 8 | World AABB off declared outer size | | 9 | LOD ratio band (--skip-decimate lands here) | | 10 | Framing gate (render path only) | | 11 | Collider triangle count above ceiling | | 12 | Bake did not finish or image has no data | | 13 | Export file missing or empty | | 14 | --output produced no file |

+
+
+

Source

+
+ showcase/wooden-barrel/wooden_barrel.py + View on GitHub → +
+ 
"""Game-ready wooden barrel — a showcase piece, not an example.
+
+Asserts budget conformance of a procedural staved barrel after composing
+shipped pipeline pieces: bmesh construction, UVs, two materials, high-to-low
+normal bake, LOD chain, convex collider, Unity glTF export.
+
+Budgets are declared below and recomputed from the generated result.
+They are not API-contract witnesses. ``--skip-decimate`` skips the LOD
+DECIMATE stage so the LOD-ratio budget fails.
+
+No RNG. Construction is closed-form. DECIMATE COLLAPSE triangle counts
+are not byte-identical across Blender versions — the LOD gate is a
+ratio band, not an exact count.
+
+    blender --background --python wooden_barrel.py --
+    blender --background --python wooden_barrel.py -- --skip-decimate
+    blender --background --python wooden_barrel.py -- --output barrel.png
+"""
+import argparse
+import math
+import os
+import sys
+import tempfile
+import traceback
+
+import bmesh
+import bpy
+from mathutils import Euler, Vector
+
+# Showcase lives at repo-root/showcase/, not under examples/. The framing
+# helper is the repo's only shared import and lives next to the examples;
+# resolve the repo root so we do not move gallery_framing.py.
+_REPO = os.path.abspath(
+    os.path.join(os.path.dirname(os.path.abspath(__file__)), os.pardir, os.pardir)
+)
+sys.path.insert(0, os.path.join(_REPO, "examples"))
+sys.dont_write_bytecode = True
+import gallery_framing  # noqa: E402
+
+HEIGHT = 0.88
+R_END = 0.27
+R_MID = 0.36
+N_STAVES = 12
+STAVE_THICK = 0.030
+N_RINGS = 5
+STAVE_GAP = 0.05
+HOOP_ZS = (0.10, 0.28, 0.60, 0.78)
+HOOP_H = 0.042
+HOOP_PAD = 0.014
+LID_T = 0.030
+BBOX_TOL = 0.01
+OUTER_SIZE = (0.719, 0.719, 0.880)
+
+BASE_TRIS_MIN = 4200
+BASE_TRIS_MAX = 4450
+LOD1_RATIO_MIN = 0.32
+LOD1_RATIO_MAX = 0.62
+LOD2_RATIO_MIN = 0.10
+LOD2_RATIO_MAX = 0.35
+LOD1_TARGET = 0.50
+LOD2_TARGET = 0.22
+MATERIAL_COUNT = 2
+UV_EPS = 1e-4
+UV_OVERLAP_MAX = 1e-5
+COLLIDER_TRIS_MAX = 400
+BAKE_RES = 256
+CAGE_EXTRUSION = 0.05
+
+WOOD_IDX = 0
+METAL_IDX = 1
+
+
+def eevee_engine_id():
+    return "BLENDER_EEVEE" if bpy.app.version >= (5, 0, 0) else "BLENDER_EEVEE_NEXT"
+
+
+def fail(msg, code):
+    print(f"ERROR: {msg}", file=sys.stderr)
+    return code
+
+
+def triangle_count(mesh):
+    mesh.calc_loop_triangles()
+    return len(mesh.loop_triangles)
+
+
+def evaluated_triangle_count(obj):
+    # Duplicated from snippets/lod_chain.py / decimate_to_budget.py (not a package).
+    depsgraph = bpy.context.evaluated_depsgraph_get()
+    eval_obj = obj.evaluated_get(depsgraph)
+    eval_mesh = eval_obj.to_mesh()
+    try:
+        eval_mesh.calc_loop_triangles()
+        return len(eval_mesh.loop_triangles)
+    finally:
+        eval_obj.to_mesh_clear()
+
+
+def radius_at(z):
+    return R_END + (R_MID - R_END) * math.sin(math.pi * z / HEIGHT)
+
+
+def add_cone(bm, loc, radius1, radius2, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)):
+    geo = bmesh.ops.create_cone(
+        bm,
+        cap_ends=True,
+        cap_tris=False,
+        segments=segments,
+        radius1=radius1,
+        radius2=radius2,
+        depth=depth,
+    )
+    verts = list(geo["verts"])
+    rot = Euler(euler).to_matrix()
+    origin = Vector(loc)
+    for v in verts:
+        v.co = rot @ v.co + origin
+    bm.faces.ensure_lookup_table()
+    faces = {f for v in verts for f in v.link_faces}
+    for f in faces:
+        f.material_index = mat_idx
+    return verts
+
+
+def add_cylinder(bm, loc, radius, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)):
+    return add_cone(bm, loc, radius, radius, depth, segments, mat_idx, euler=euler)
+
+
+def pack_uvs(bm, margin=0.08):
+    uv = bm.loops.layers.uv.new("UVMap")
+    faces = list(bm.faces)
+    n = len(faces)
+    cols = max(1, math.ceil(math.sqrt(n)))
+    rows = max(1, math.ceil(n / cols))
+    cell_w = 1.0 / cols
+    cell_h = 1.0 / rows
+    pad_u = margin * cell_w * 0.5
+    pad_v = margin * cell_h * 0.5
+    usable_w = cell_w - 2.0 * pad_u
+    usable_h = cell_h - 2.0 * pad_v
+    for i, face in enumerate(faces):
+        col = i % cols
+        row = i // cols
+        nrm = face.normal
+        ax = abs(nrm.x)
+        ay = abs(nrm.y)
+        az = abs(nrm.z)
+        coords = []
+        for loop in face.loops:
+            co = loop.vert.co
+            if az >= ax and az >= ay:
+                coords.append((co.x, co.y))
+            elif ax >= ay:
+                coords.append((co.y, co.z))
+            else:
+                coords.append((co.x, co.z))
+        xs = [c[0] for c in coords]
+        ys = [c[1] for c in coords]
+        minx, maxx = min(xs), max(xs)
+        miny, maxy = min(ys), max(ys)
+        dx = max(maxx - minx, 1e-8)
+        dy = max(maxy - miny, 1e-8)
+        origin_u = col * cell_w + pad_u
+        origin_v = row * cell_h + pad_v
+        for loop, (x, y) in zip(face.loops, coords):
+            loop[uv].uv = (
+                origin_u + (x - minx) / dx * usable_w,
+                origin_v + (y - miny) / dy * usable_h,
+            )
+
+
+def build_barrel_mesh(name, bevel_offset, bevel_segments):
+    bm = bmesh.new()
+    stave_verts = []
+    try:
+        zs = [HEIGHT * i / (N_RINGS - 1) for i in range(N_RINGS)]
+        for i in range(N_STAVES):
+            a0 = 2.0 * math.pi * i / N_STAVES
+            a1 = 2.0 * math.pi * (i + 1.0 - STAVE_GAP) / N_STAVES
+            outer = []
+            inner = []
+            for z in zs:
+                r = radius_at(z)
+                ov = (
+                    bm.verts.new((r * math.cos(a0), r * math.sin(a0), z)),
+                    bm.verts.new((r * math.cos(a1), r * math.sin(a1), z)),
+                )
+                ri = r - STAVE_THICK
+                iv = (
+                    bm.verts.new((ri * math.cos(a0), ri * math.sin(a0), z)),
+                    bm.verts.new((ri * math.cos(a1), ri * math.sin(a1), z)),
+                )
+                outer.append(ov)
+                inner.append(iv)
+                stave_verts.extend(ov)
+                stave_verts.extend(iv)
+            for k in range(N_RINGS - 1):
+                o0a, o0b = outer[k]
+                o1a, o1b = outer[k + 1]
+                i0a, i0b = inner[k]
+                i1a, i1b = inner[k + 1]
+                for vs in (
+                    (o0a, o1a, o1b, o0b),
+                    (i0b, i1b, i1a, i0a),
+                    (o0a, i0a, i1a, o1a),
+                    (o0b, o1b, i1b, i0b),
+                ):
+                    face = bm.faces.new(vs)
+                    face.material_index = WOOD_IDX
+            top = bm.faces.new((outer[-1][0], outer[-1][1], inner[-1][1], inner[-1][0]))
+            top.material_index = WOOD_IDX
+            bot = bm.faces.new((outer[0][1], outer[0][0], inner[0][0], inner[0][1]))
+            bot.material_index = WOOD_IDX
+
+        if bevel_offset > 0.0:
+            edges = list({e for v in stave_verts for e in v.link_edges})
+            bmesh.ops.bevel(
+                bm,
+                geom=edges,
+                offset=bevel_offset,
+                segments=bevel_segments,
+                profile=0.5,
+                affect="EDGES",
+                clamp_overlap=True,
+            )
+
+        add_cylinder(bm, (0.0, 0.0, LID_T / 2.0), R_END - 0.012, LID_T, 16, WOOD_IDX)
+        add_cylinder(
+            bm, (0.0, 0.0, HEIGHT - LID_T / 2.0), R_END - 0.012, LID_T, 16, WOOD_IDX,
+        )
+        hoop_faces = set()
+        for z in HOOP_ZS:
+            before = set(bm.faces)
+            add_cylinder(
+                bm,
+                (0.0, 0.0, z),
+                radius_at(z) + HOOP_PAD,
+                HOOP_H,
+                20,
+                METAL_IDX,
+            )
+            hoop_faces.update(set(bm.faces) - before)
+
+        pack_uvs(bm)
+        bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces))
+        for face in bm.faces:
+            face.smooth = True
+        for edge in bm.edges:
+            edge.smooth = True
+            if edge.is_manifold and len(edge.link_faces) == 2:
+                if edge.calc_face_angle() > math.radians(35.0):
+                    edge.smooth = False
+        for f in hoop_faces:
+            if f.is_valid:
+                f.material_index = METAL_IDX
+        me = bpy.data.meshes.new(name)
+        bm.to_mesh(me)
+        me.update()
+    finally:
+        bm.free()
+    obj = bpy.data.objects.new(name, me)
+    bpy.context.collection.objects.link(obj)
+    return obj
+
+
+def principled(name, color, metallic, roughness):
+    mat = bpy.data.materials.new(name)
+    mat.use_nodes = True
+    bsdf = mat.node_tree.nodes["Principled BSDF"]
+    bsdf.inputs["Base Color"].default_value = color
+    bsdf.inputs["Metallic"].default_value = metallic
+    bsdf.inputs["Roughness"].default_value = roughness
+    return mat
+
+
+def assign_slots(obj, wood, metal):
+    # Do not materials.clear() — that resets polygon material_index to 0
+    # on this Blender, which would drop hoop faces onto wood.
+    mats = obj.data.materials
+    if len(mats) == 0:
+        mats.append(wood)
+        mats.append(metal)
+        return
+    mats[0] = wood
+    if len(mats) == 1:
+        mats.append(metal)
+    else:
+        mats[1] = metal
+
+
+def world_bbox(obj):
+    corners = [obj.matrix_world @ Vector(c) for c in obj.bound_box]
+    xs = [c.x for c in corners]
+    ys = [c.y for c in corners]
+    zs = [c.z for c in corners]
+    return (min(xs), min(ys), min(zs), max(xs), max(ys), max(zs))
+
+
+def uv_stats(mesh):
+    uv = mesh.uv_layers.active
+    if uv is None:
+        return 0.0, 0.0, 1.0, 1.0, 0, 1.0
+    data = uv.data
+    us = [loop.uv[0] for loop in data]
+    vs = [loop.uv[1] for loop in data]
+    aabbs = []
+    for poly in mesh.polygons:
+        pu = [data[i].uv[0] for i in poly.loop_indices]
+        pv = [data[i].uv[1] for i in poly.loop_indices]
+        aabbs.append((min(pu), min(pv), max(pu), max(pv)))
+    overlap = 0.0
+    for i in range(len(aabbs)):
+        a = aabbs[i]
+        for j in range(i + 1, len(aabbs)):
+            b = aabbs[j]
+            x0 = max(a[0], b[0])
+            y0 = max(a[1], b[1])
+            x1 = min(a[2], b[2])
+            y1 = min(a[3], b[3])
+            overlap += max(0.0, x1 - x0) * max(0.0, y1 - y0)
+    return min(us), min(vs), max(us), max(vs), overlap, len(aabbs)
+
+
+def make_lod(obj, name, ratio, skip_decimate):
+    mesh = obj.data.copy()
+    lod = bpy.data.objects.new(name, mesh)
+    lod.matrix_world = obj.matrix_world.copy()
+    bpy.context.scene.collection.objects.link(lod)
+    if not skip_decimate and 0.0 < ratio < 1.0:
+        mod = lod.modifiers.new("DecimateBudget", "DECIMATE")
+        mod.decimate_type = "COLLAPSE"
+        mod.ratio = ratio
+    return lod
+
+
+def convex_hull_collider(obj, name):
+    # Duplicated from snippets/convex_hull_collider.py (not a package).
+    mesh = bpy.data.meshes.new(name)
+    bm = bmesh.new()
+    try:
+        bm.from_mesh(obj.data)
+        result = bmesh.ops.convex_hull(bm, input=list(bm.verts))
+        interior = result.get("geom_interior") or []
+        unused = result.get("geom_unused") or []
+        if interior:
+            bmesh.ops.delete(bm, geom=interior, context="VERTS")
+        if unused:
+            bmesh.ops.delete(bm, geom=unused, context="VERTS")
+        bm.to_mesh(mesh)
+        mesh.update()
+    finally:
+        bm.free()
+    collider = bpy.data.objects.new(name, mesh)
+    bpy.context.collection.objects.link(collider)
+    collider.matrix_world = obj.matrix_world.copy()
+    return collider
+
+
+def setup_bake_image(obj, target_mat, size=BAKE_RES):
+    # Adapted from snippets/setup_bake_target_image.py — do not replace slots.
+    if not obj.data.uv_layers:
+        return None, None
+    img = bpy.data.images.new("BarrelNrm", size, size, alpha=True, float_buffer=False)
+    img.colorspace_settings.name = "Non-Color"
+    nodes = target_mat.node_tree.nodes
+    tex = nodes.new("ShaderNodeTexImage")
+    tex.image = img
+    nodes.active = tex
+    tex.select = True
+    obj.active_material_index = WOOD_IDX
+    return img, tex
+
+
+def bake_normal(high, low):
+    # Duplicated from snippets/bake_normal_high_to_low.py (not a package).
+    scene = bpy.context.scene
+    scene.render.engine = "CYCLES"
+    scene.cycles.device = "CPU"
+    scene.cycles.samples = 1
+    scene.cycles.use_denoising = False
+    for ob in bpy.context.view_layer.objects:
+        ob.select_set(False)
+    high.select_set(True)
+    low.select_set(True)
+    bpy.context.view_layer.objects.active = low
+    return bpy.ops.object.bake(
+        type="NORMAL",
+        use_selected_to_active=True,
+        cage_extrusion=CAGE_EXTRUSION,
+        use_cage=False,
+        normal_space="TANGENT",
+        margin=4,
+        margin_type="ADJACENT_FACES",
+        use_clear=True,
+        target="IMAGE_TEXTURES",
+    )
+
+
+def export_unity(path, objects):
+    # Duplicated from snippets/export_preset_unity.py (not a package).
+    for ob in bpy.context.view_layer.objects:
+        ob.select_set(False)
+    for ob in objects:
+        ob.select_set(True)
+    bpy.context.view_layer.objects.active = objects[0]
+    bpy.ops.export_scene.gltf(
+        filepath=path,
+        use_selection=True,
+        export_yup=True,
+        export_apply=True,
+        export_draco_mesh_compression_enable=False,
+        export_animations=False,
+    )
+
+
+def check(skip_decimate):
+    bpy.ops.wm.read_factory_settings(use_empty=True)
+    low = build_barrel_mesh("BarrelLow", bevel_offset=0.006, bevel_segments=2)
+    high = build_barrel_mesh("BarrelHigh", bevel_offset=0.006, bevel_segments=4)
+    wood = principled("BarrelWood", (0.48, 0.22, 0.07, 1.0), 0.0, 0.50)
+    metal = principled("BarrelMetal", (0.62, 0.60, 0.56, 1.0), 1.0, 0.22)
+    assign_slots(low, wood, metal)
+    assign_slots(high, wood, metal)
+
+    if low.data is None or len(low.data.polygons) < 6:
+        return fail("barrel mesh did not build", 3), None, None, None, None, None
+
+    base_tris = triangle_count(low.data)
+    mats = [s for s in low.data.materials if s is not None]
+    nmat = len(mats)
+    distinct_mats = len({id(s) for s in mats})
+    idx_counts = {}
+    for poly in low.data.polygons:
+        idx_counts[poly.material_index] = idx_counts.get(poly.material_index, 0) + 1
+    print(f"measured mat_index_counts={idx_counts}")
+    u0, v0, u1, v1, overlap, nfaces = uv_stats(low.data)
+    bb = world_bbox(low)
+    size_x = bb[3] - bb[0]
+    size_y = bb[4] - bb[1]
+    size_z = bb[5] - bb[2]
+
+    img, tex = setup_bake_image(low, wood)
+    if img is None:
+        return fail("barrel has no UV layer", 3), None, None, None, None, None
+    bake_result = bake_normal(high, low)
+
+    lod1 = make_lod(low, "BarrelLOD1", LOD1_TARGET, skip_decimate)
+    lod2 = make_lod(low, "BarrelLOD2", LOD2_TARGET, skip_decimate)
+    bpy.context.view_layer.update()
+    lod1_tris = evaluated_triangle_count(lod1)
+    lod2_tris = evaluated_triangle_count(lod2)
+    r1 = lod1_tris / base_tris if base_tris else 0.0
+    r2 = lod2_tris / base_tris if base_tris else 0.0
+
+    collider_src = build_barrel_mesh("BarrelColSrc", bevel_offset=0.0, bevel_segments=1)
+    collider = convex_hull_collider(collider_src, "BarrelCollider")
+    bpy.data.objects.remove(collider_src, do_unlink=True)
+    col_tris = triangle_count(collider.data)
+
+    export_path = os.path.join(
+        tempfile.gettempdir(),
+        f"bdt_wooden_barrel_{os.getpid()}.glb",
+    )
+    if os.path.exists(export_path):
+        os.remove(export_path)
+    export_unity(export_path, [low, collider])
+    export_size = os.path.getsize(export_path) if os.path.isfile(export_path) else 0
+
+    print(
+        f"blender={tuple(bpy.app.version)} skip_decimate={skip_decimate}"
+    )
+    print(
+        f"measured base_tris={base_tris} lod1_tris={lod1_tris} "
+        f"lod2_tris={lod2_tris} r1={r1:.4f} r2={r2:.4f}"
+    )
+    print(
+        f"measured nmat={nmat} uv=({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f}) "
+        f"overlap={overlap:.6f} nfaces={nfaces}"
+    )
+    print(
+        f"measured bbox=({size_x:.4f},{size_y:.4f},{size_z:.4f}) "
+        f"outer={OUTER_SIZE} zmin={bb[2]:.4f}"
+    )
+    print(
+        f"measured collider_tris={col_tris} bake={bake_result} "
+        f"bake_has_data={img.has_data} export_bytes={export_size}"
+    )
+
+    if not (BASE_TRIS_MIN <= base_tris <= BASE_TRIS_MAX):
+        return fail(
+            f"base tris {base_tris} not in [{BASE_TRIS_MIN}, {BASE_TRIS_MAX}]",
+            4,
+        ), None, None, None, None, None
+    if nmat != MATERIAL_COUNT or distinct_mats != MATERIAL_COUNT:
+        return fail(
+            f"material slots {nmat} distinct {distinct_mats} != {MATERIAL_COUNT}",
+            5,
+        ), None, None, None, None, None
+    if idx_counts.get(METAL_IDX, 0) < 16:
+        return fail(
+            f"metal hoop faces {idx_counts.get(METAL_IDX, 0)} < 16",
+            5,
+        ), None, None, None, None, None
+    if u0 < -UV_EPS or v0 < -UV_EPS or u1 > 1.0 + UV_EPS or v1 > 1.0 + UV_EPS:
+        return fail(
+            f"UVs outside 0..1: ({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f})",
+            6,
+        ), None, None, None, None, None
+    if overlap > UV_OVERLAP_MAX:
+        return fail(
+            f"UV AABB overlap {overlap:.6f} > {UV_OVERLAP_MAX}",
+            7,
+        ), None, None, None, None, None
+    if (
+        abs(size_x - OUTER_SIZE[0]) > BBOX_TOL
+        or abs(size_y - OUTER_SIZE[1]) > BBOX_TOL
+        or abs(size_z - OUTER_SIZE[2]) > BBOX_TOL
+    ):
+        return fail(
+            f"bbox ({size_x:.4f},{size_y:.4f},{size_z:.4f}) "
+            f"off outer {OUTER_SIZE}",
+            8,
+        ), None, None, None, None, None
+    if not (LOD1_RATIO_MIN <= r1 <= LOD1_RATIO_MAX):
+        return fail(
+            f"LOD1 ratio {r1:.4f} not in [{LOD1_RATIO_MIN}, {LOD1_RATIO_MAX}] "
+            "(--skip-decimate is the designed fail)",
+            9,
+        ), None, None, None, None, None
+    if not (LOD2_RATIO_MIN <= r2 <= LOD2_RATIO_MAX):
+        return fail(
+            f"LOD2 ratio {r2:.4f} not in [{LOD2_RATIO_MIN}, {LOD2_RATIO_MAX}]",
+            9,
+        ), None, None, None, None, None
+    if col_tris > COLLIDER_TRIS_MAX:
+        return fail(
+            f"collider tris {col_tris} > {COLLIDER_TRIS_MAX}",
+            11,
+        ), None, None, None, None, None
+    if bake_result != {"FINISHED"} or not img.has_data:
+        return fail(
+            f"bake failed result={bake_result} has_data={img.has_data}",
+            12,
+        ), None, None, None, None, None
+    if export_size <= 0:
+        return fail("export file missing or empty", 13), None, None, None, None, None
+    return 0, low, high, wood, tex, collider
+
+
+def wire_normal(mat, tex):
+    nt = mat.node_tree
+    bsdf = nt.nodes["Principled BSDF"]
+    nrm = nt.nodes.new("ShaderNodeNormalMap")
+    nrm.inputs["Strength"].default_value = 1.0
+    nt.links.new(tex.outputs["Color"], nrm.inputs["Color"])
+    nt.links.new(nrm.outputs["Normal"], bsdf.inputs["Normal"])
+
+
+def render_still(low, wood, tex, path, engine):
+    scene = bpy.context.scene
+    wire_normal(wood, tex)
+    for ob in list(scene.objects):
+        if ob.type == "MESH" and ob != low:
+            ob.hide_render = True
+            ob.hide_viewport = True
+
+    low.rotation_euler.z = math.radians(-32.0)
+    low.rotation_euler.x = math.radians(4.0)
+
+    floor_me = bpy.data.meshes.new("Floor")
+    bm = bmesh.new()
+    try:
+        bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0)
+        bm.to_mesh(floor_me)
+    finally:
+        bm.free()
+    fmat = bpy.data.materials.new("Floor")
+    fmat.use_nodes = True
+    fb = fmat.node_tree.nodes["Principled BSDF"]
+    fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0)
+    fb.inputs["Roughness"].default_value = 0.7
+    floor_me.materials.append(fmat)
+    floor = bpy.data.objects.new("Floor", floor_me)
+    scene.collection.objects.link(floor)
+    wall = bpy.data.objects.new("Wall", floor_me.copy())
+    wall.location = (0.0, 8.5, 0.0)
+    wall.rotation_euler = (math.radians(90), 0.0, 0.0)
+    scene.collection.objects.link(wall)
+
+    world = bpy.data.worlds.new("World")
+    world.use_nodes = True
+    world.node_tree.nodes["Background"].inputs["Color"].default_value = (
+        0.02, 0.021, 0.025, 1.0,
+    )
+    scene.world = world
+
+    def light(name, loc, energy, size, col, rot):
+        ld = bpy.data.lights.new(name, "AREA")
+        ld.energy = energy
+        ld.size = size
+        ld.color = col
+        ob = bpy.data.objects.new(name, ld)
+        ob.location = loc
+        ob.rotation_euler = tuple(math.radians(a) for a in rot)
+        scene.collection.objects.link(ob)
+
+    light("Key", (-3.6, -5.0, 5.8), 680.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36))
+    light("Fill", (5.0, -3.6, 2.6), 48.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50))
+    light("Wedge", (2.4, 4.2, 4.1), 640.0, 5.5, (1.0, 0.70, 0.40), (-70, 0, 198))
+
+    cam_data = bpy.data.cameras.new("Cam")
+    cam_data.lens = 50.0
+    cam = bpy.data.objects.new("Cam", cam_data)
+    cam.location = (1.68, -2.38, 1.38)
+    scene.collection.objects.link(cam)
+    aim = bpy.data.objects.new("Aim", None)
+    aim.location = (0.0, 0.0, HEIGHT / 2.0 + 0.02)
+    scene.collection.objects.link(aim)
+    con = cam.constraints.new("TRACK_TO")
+    con.target = aim
+    con.track_axis = "TRACK_NEGATIVE_Z"
+    con.up_axis = "UP_Y"
+    scene.camera = cam
+
+    scene.render.engine = "CYCLES" if engine == "cycles" else eevee_engine_id()
+    if engine == "cycles":
+        scene.cycles.samples = 32
+        scene.cycles.device = "CPU"
+    else:
+        try:
+            scene.eevee.taa_render_samples = 64
+        except AttributeError:
+            pass
+    scene.render.resolution_x = 1280
+    scene.render.resolution_y = 720
+    scene.render.image_settings.file_format = (
+        "WEBP" if path.lower().endswith(".webp") else "PNG"
+    )
+    if path.lower().endswith(".webp"):
+        scene.render.image_settings.quality = 90
+    scene.render.filepath = path
+    scene.view_settings.view_transform = "Standard"
+
+    fcode = gallery_framing.check_framing(
+        scene, cam, hero=[low], elements=[low], stage=[floor, wall],
+    )
+    if fcode:
+        return fcode
+    bpy.ops.render.render(write_still=True)
+    if not (os.path.exists(path) and os.path.getsize(path) > 0):
+        return fail("render produced no file", 14)
+    return 0
+
+
+def main():
+    argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []
+    p = argparse.ArgumentParser()
+    p.add_argument("--output", default=None)
+    p.add_argument("--engine", default="eevee", choices=("eevee", "cycles"))
+    p.add_argument(
+        "--skip-decimate",
+        action="store_true",
+        help="falsification: skip the LOD DECIMATE stage",
+    )
+    args = p.parse_args(argv)
+
+    code, low, _high, wood, tex, _col = check(args.skip_decimate)
+    if code:
+        return code
+    if args.output:
+        rcode = render_still(low, wood, tex, os.path.abspath(args.output), args.engine)
+        if rcode:
+            return rcode
+        print(f"rendered still {args.output}")
+    print("wooden-barrel OK")
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        sys.exit(main())
+    except Exception as e:
+        traceback.print_exc()
+        print(f"FATAL: {e}", file=sys.stderr)
+        sys.exit(1)
+
+
+
+ +
+
+ generated from examples/gallery.json + CC-BY-NC-ND-4.0 + exit 0 +
+
+ + + diff --git a/showcase/gallery.json b/showcase/gallery.json index 60995b5..eadb323 100644 --- a/showcase/gallery.json +++ b/showcase/gallery.json @@ -16,6 +16,30 @@ "mesh", "export" ] + }, + { + "name": "stone-well", + "dir": "showcase/stone-well", + "teaches": "A procedural stone well through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.", + "witnessesFix": "Recomputed: 8388 tris, three materials, UVs in 0..1 with zero AABB overlap, outer AABB 1.640×1.640×1.688 m, LOD ratios in band, convex collider 230 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.", + "hero": "docs/gallery/assets/stone-well-hero.webp", + "preview": "showcase/stone-well/preview.webp", + "tags": [ + "mesh", + "export" + ] + }, + { + "name": "wooden-barrel", + "dir": "showcase/wooden-barrel", + "teaches": "A procedural staved barrel through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.", + "witnessesFix": "Recomputed: 4312 tris, two materials with 88 metal hoop faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.719×0.719×0.880 m, LOD ratios in band, convex collider 372 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.", + "hero": "docs/gallery/assets/wooden-barrel-hero.webp", + "preview": "showcase/wooden-barrel/preview.webp", + "tags": [ + "mesh", + "export" + ] } ] } diff --git a/showcase/stone-well/README.md b/showcase/stone-well/README.md new file mode 100644 index 0000000..189421d --- /dev/null +++ b/showcase/stone-well/README.md @@ -0,0 +1,73 @@ +# Stone well + +A showcase piece, not an example. Procedural round stone well (running-bond +bricks, curb, four posts, shingled pyramid roof, windlass, rope, bucket) +then the shipped pipeline: unique-cell UVs, Cycles high-to-low normal bake, +LOD chain, convex collider, Unity glTF export. + +It asserts **budget conformance** of the generated result. It does not +witness an API contract. "It rendered without error" is not a check. + +**Composes** skills `mesh-editing-and-bmesh`, `bake-high-to-low`, +`depsgraph-and-evaluated-data`, `engine-export-presets`, and snippets +`bake_normal_high_to_low.py`, `setup_bake_target_image.py`, +`lod_chain.py` / `decimate_to_budget.py`, `convex_hull_collider.py`, +`export_preset_unity.py` (helpers copied, not imported as a package). + +## Budgets + +Declared as named constants; every gate **recomputes** from the mesh, +materials, UVs, evaluated LOD, collider, or export file. + +| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) | +| --- | --- | --- | +| Base triangles | 8280–8500 | 8388 / 8388 / 8388 | +| LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | +| LOD2 ratio | 0.10–0.35 of base | 0.2198 / 0.2198 / 0.2198 | +| Materials | exactly 3 distinct | 3 | +| UVs | in `0..1`, AABB overlap ≤ 1e-5 | in range, overlap 0 | +| Outer AABB | (1.640, 1.640, 1.688) m ± 0.01 | (1.6400, 1.6400, 1.6882), zmin 0 | +| Collider tris | ≤ 260 | 230 | +| Export | written, size > 0 | 601028 / 601092 / 601372 bytes | + +DECIMATE COLLAPSE triangle counts are **not** guaranteed identical across +series — the gate is a ratio band, not an exact count. This mesh happened +to match on 4.5.11 / 5.1.2 / 5.2.1. Bake pixels are stochastic; the gate +is `has_data` plus operator `FINISHED`, not byte-identity. Construction +uses no RNG. glTF byte size differs by a few hundred bytes across series. + +`--skip-decimate` skips the LOD DECIMATE stage so LOD1 ratio is 1.0 and +exit 9 fires. That is the named budget the falsifier violates. + +## Run + +```bash +blender --background --python stone_well.py -- +blender --background --python stone_well.py -- --skip-decimate +blender --background --python stone_well.py -- --output well.png +``` + +Smoke does not pass `--output` or `--skip-decimate`. + +## Exit codes + +File-local. `9` is a valid check code. `10` is reserved for +`gallery_framing.check_framing` on the `--output` path. + +| Code | Meaning | +| --- | --- | +| 0 | Success | +| 1 | Uncaught exception (FATAL wrapper) | +| 2 | argparse / usage | +| 3 | Mesh did not build / no UV layer | +| 4 | Base triangle count outside range | +| 5 | Material count ≠ 3 distinct slots | +| 6 | UVs outside 0..1 | +| 7 | UV AABB overlap above tolerance | +| 8 | World AABB off declared outer size | +| 9 | LOD ratio band (`--skip-decimate` lands here) | +| 10 | Framing gate (render path only) | +| 11 | Collider triangle count above ceiling | +| 12 | Bake did not finish or image has no data | +| 13 | Export file missing or empty | +| 14 | `--output` produced no file | diff --git a/showcase/stone-well/preview.webp b/showcase/stone-well/preview.webp new file mode 100644 index 0000000..62ae041 Binary files /dev/null and b/showcase/stone-well/preview.webp differ diff --git a/showcase/stone-well/stone_well.py b/showcase/stone-well/stone_well.py new file mode 100644 index 0000000..e363bab --- /dev/null +++ b/showcase/stone-well/stone_well.py @@ -0,0 +1,821 @@ +"""Game-ready stone well — a showcase piece, not an example. + +Asserts budget conformance of a procedural well after composing shipped +pipeline pieces: bmesh construction, UVs, three materials, high-to-low +normal bake, LOD chain, convex collider, Unity glTF export. + +Budgets are declared below and recomputed from the generated result. +They are not API-contract witnesses. ``--skip-decimate`` skips the LOD +DECIMATE stage so the LOD-ratio budget fails. + +No RNG. Construction is closed-form. DECIMATE COLLAPSE triangle counts +are not byte-identical across Blender versions — the LOD gate is a +ratio band, not an exact count. + + blender --background --python stone_well.py -- + blender --background --python stone_well.py -- --skip-decimate + blender --background --python stone_well.py -- --output well.png +""" +import argparse +import math +import os +import sys +import tempfile +import traceback + +import bmesh +import bpy +from mathutils import Euler, Vector + +# Showcase lives at repo-root/showcase/, not under examples/. The framing +# helper is the repo's only shared import and lives next to the examples; +# resolve the repo root so we do not move gallery_framing.py. +_REPO = os.path.abspath( + os.path.join(os.path.dirname(os.path.abspath(__file__)), os.pardir, os.pardir) +) +sys.path.insert(0, os.path.join(_REPO, "examples")) +sys.dont_write_bytecode = True +import gallery_framing # noqa: E402 + +# Closed-form construction. OUTER_SIZE is the AABB of eaves + peak, compared +# against the measured world bbox — not assigned onto the mesh. +N_AROUND = 12 +N_ROWS = 5 +R_INNER = 0.40 +STONE_D = 0.14 +R_OUTER = R_INNER + STONE_D +R_MID = (R_INNER + R_OUTER) / 2.0 +WALL_H = 0.72 +STONE_H = WALL_H / N_ROWS +CURB_H = 0.065 +CURB_OUT = 0.045 +POST_S = 0.068 +POST_R = 0.55 +POST_H = 0.58 +POST_BOTTOM = WALL_H + CURB_H +POST_TOP = POST_BOTTOM + POST_H +EAVE_OVERHANG = 0.22 +EAVE_HALF = POST_R + POST_S / 2.0 + EAVE_OVERHANG +EAVE_Z = POST_TOP - 0.02 +ROOF_RISE = 0.34 +PEAK_Z = EAVE_Z + ROOF_RISE +SHINGLE_T = 0.016 +WINDLASS_R = 0.045 +BUCKET_R = 0.10 +BUCKET_H = 0.14 +BUCKET_Z = 0.68 +ROPE_R = 0.016 +BBOX_TOL = 0.01 +# Fitted to the generated AABB after locking geometry. Recomputed from bound_box. +OUTER_SIZE = (1.640, 1.640, 1.688) + +# Measured after locking geometry. DECIMATE COLLAPSE ratios diverge across +# series — bands, not exact counts. Tightened after the first 4.5/5.1/5.2 run. +BASE_TRIS_MIN = 8280 +BASE_TRIS_MAX = 8500 +LOD1_RATIO_MIN = 0.32 +LOD1_RATIO_MAX = 0.62 +LOD2_RATIO_MIN = 0.10 +LOD2_RATIO_MAX = 0.35 +LOD1_TARGET = 0.50 +LOD2_TARGET = 0.22 +MATERIAL_COUNT = 3 +UV_EPS = 1e-4 +UV_OVERLAP_MAX = 1e-5 +COLLIDER_TRIS_MAX = 260 +BAKE_RES = 256 +CAGE_EXTRUSION = 0.06 + +STONE_IDX = 0 +WOOD_IDX = 1 +METAL_IDX = 2 + + +def eevee_engine_id(): + return "BLENDER_EEVEE" if bpy.app.version >= (5, 0, 0) else "BLENDER_EEVEE_NEXT" + + +def fail(msg, code): + print(f"ERROR: {msg}", file=sys.stderr) + return code + + +def triangle_count(mesh): + mesh.calc_loop_triangles() + return len(mesh.loop_triangles) + + +def evaluated_triangle_count(obj): + # Duplicated from snippets/lod_chain.py / decimate_to_budget.py (not a package). + depsgraph = bpy.context.evaluated_depsgraph_get() + eval_obj = obj.evaluated_get(depsgraph) + eval_mesh = eval_obj.to_mesh() + try: + eval_mesh.calc_loop_triangles() + return len(eval_mesh.loop_triangles) + finally: + eval_obj.to_mesh_clear() + + +def add_box(bm, loc, scale, mat_idx, euler=(0.0, 0.0, 0.0)): + geo = bmesh.ops.create_cube(bm, size=1.0) + verts = geo["verts"] + rot = Euler(euler).to_matrix() + origin = Vector(loc) + for v in verts: + p = Vector((v.co.x * scale[0], v.co.y * scale[1], v.co.z * scale[2])) + v.co = rot @ p + origin + faces = {f for v in verts for f in v.link_faces} + for f in faces: + f.material_index = mat_idx + return verts + + +def add_cone(bm, loc, radius1, radius2, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)): + geo = bmesh.ops.create_cone( + bm, + cap_ends=True, + cap_tris=False, + segments=segments, + radius1=radius1, + radius2=radius2, + depth=depth, + ) + verts = geo["verts"] + rot = Euler(euler).to_matrix() + origin = Vector(loc) + for v in verts: + v.co = rot @ v.co + origin + faces = {f for v in verts for f in v.link_faces} + for f in faces: + f.material_index = mat_idx + return verts + + +def add_cylinder(bm, loc, radius, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)): + return add_cone(bm, loc, radius, radius, depth, segments, mat_idx, euler=euler) + + +def pack_uvs(bm, margin=0.08): + uv = bm.loops.layers.uv.new("UVMap") + faces = list(bm.faces) + n = len(faces) + cols = max(1, math.ceil(math.sqrt(n))) + rows = max(1, math.ceil(n / cols)) + cell_w = 1.0 / cols + cell_h = 1.0 / rows + pad_u = margin * cell_w * 0.5 + pad_v = margin * cell_h * 0.5 + usable_w = cell_w - 2.0 * pad_u + usable_h = cell_h - 2.0 * pad_v + for i, face in enumerate(faces): + col = i % cols + row = i // cols + nrm = face.normal + ax = abs(nrm.x) + ay = abs(nrm.y) + az = abs(nrm.z) + coords = [] + for loop in face.loops: + co = loop.vert.co + if az >= ax and az >= ay: + coords.append((co.x, co.y)) + elif ax >= ay: + coords.append((co.y, co.z)) + else: + coords.append((co.x, co.z)) + xs = [c[0] for c in coords] + ys = [c[1] for c in coords] + minx, maxx = min(xs), max(xs) + miny, maxy = min(ys), max(ys) + dx = max(maxx - minx, 1e-8) + dy = max(maxy - miny, 1e-8) + origin_u = col * cell_w + pad_u + origin_v = row * cell_h + pad_v + for loop, (x, y) in zip(face.loops, coords): + loop[uv].uv = ( + origin_u + (x - minx) / dx * usable_w, + origin_v + (y - miny) / dy * usable_h, + ) + + +def build_well_mesh(name, bevel_offset, bevel_segments): + bm = bmesh.new() + stone_verts = [] + try: + stone_w = 2.0 * R_MID * math.tan(math.pi / N_AROUND) * 0.88 + actual_h = STONE_H * 0.90 + for row in range(N_ROWS): + z = actual_h / 2.0 + row * STONE_H + rot_off = (row % 2) * (math.pi / N_AROUND) + for i in range(N_AROUND): + ang = 2.0 * math.pi * i / N_AROUND + rot_off + loc = (R_MID * math.cos(ang), R_MID * math.sin(ang), z) + stone_verts.extend( + add_box( + bm, + loc, + (STONE_D, stone_w, actual_h), + STONE_IDX, + euler=(0.0, 0.0, ang), + ) + ) + + curb_r = R_OUTER + CURB_OUT / 2.0 + curb_w = 2.0 * curb_r * math.tan(math.pi / N_AROUND) * 0.90 + curb_z = WALL_H + CURB_H / 2.0 + for i in range(N_AROUND): + ang = 2.0 * math.pi * i / N_AROUND + loc = (curb_r * math.cos(ang), curb_r * math.sin(ang), curb_z) + stone_verts.extend( + add_box( + bm, + loc, + (STONE_D + CURB_OUT, curb_w, CURB_H), + STONE_IDX, + euler=(0.0, 0.0, ang), + ) + ) + + if bevel_offset > 0.0: + edges = list({e for v in stone_verts for e in v.link_edges}) + bmesh.ops.bevel( + bm, + geom=edges, + offset=bevel_offset, + segments=bevel_segments, + profile=0.5, + affect="EDGES", + clamp_overlap=True, + ) + + post_angles = (0.0, math.pi / 2.0, math.pi, 3.0 * math.pi / 2.0) + for ang in post_angles: + loc = ( + POST_R * math.cos(ang), + POST_R * math.sin(ang), + POST_BOTTOM + POST_H / 2.0, + ) + add_box(bm, loc, (POST_S, POST_S, POST_H), WOOD_IDX) + + beam_z = POST_TOP - 0.05 + add_box( + bm, + (0.0, 0.0, beam_z), + (POST_R * 2.0 - POST_S, POST_S * 0.85, POST_S * 0.85), + WOOD_IDX, + ) + add_cylinder( + bm, + (0.0, 0.0, beam_z), + WINDLASS_R, + POST_R * 2.0 - POST_S * 1.4, + 12, + WOOD_IDX, + euler=(0.0, math.pi / 2.0, 0.0), + ) + add_box( + bm, + (POST_R - POST_S * 0.2, 0.0, beam_z), + (0.018, 0.12, 0.018), + METAL_IDX, + euler=(0.0, 0.0, math.radians(25.0)), + ) + + pitch = math.atan(ROOF_RISE / EAVE_HALF) + r_base = EAVE_HALF * math.sqrt(2.0) + add_cone( + bm, + (0.0, 0.0, (EAVE_Z + PEAK_Z) / 2.0), + r_base, + 0.04, + ROOF_RISE, + 4, + WOOD_IDX, + euler=(0.0, 0.0, math.pi / 4.0), + ) + nrm_local = Vector((0.0, ROOF_RISE, EAVE_HALF)).normalized() + + def add_course(yaw, t0, t1): + rot = Euler((0.0, 0.0, yaw)).to_matrix() + nrm = rot @ nrm_local + + def pt(t, s): + w = EAVE_HALF * t + y = t * EAVE_HALF + z = PEAK_Z - t * ROOF_RISE + return rot @ Vector((s * w, y, z)) + + inner = SHINGLE_T * 0.12 + outer = SHINGLE_T * 1.05 + corners = ( + pt(t0, -1.0), + pt(t0, 1.0), + pt(t1, 1.0), + pt(t1, -1.0), + ) + vs = [bm.verts.new(c + nrm * inner) for c in corners] + vs.extend(bm.verts.new(c + nrm * outer) for c in corners) + idx = ( + (0, 1, 2, 3), + (4, 7, 6, 5), + (0, 4, 5, 1), + (1, 5, 6, 2), + (2, 6, 7, 3), + (3, 7, 4, 0), + ) + for a, b, c, d in idx: + face = bm.faces.new((vs[a], vs[b], vs[c], vs[d])) + face.material_index = WOOD_IDX + + n_rows = 5 + for side in range(4): + yaw = side * (math.pi / 2.0) + for row in range(n_rows): + t0 = (row + 0.18) / n_rows + t1 = (row + 1.08) / n_rows + if t1 > 1.0: + t1 = 1.0 + add_course(yaw, t0, t1) + fascia_h = 0.045 + fascia_t = 0.032 + for side in range(4): + yaw = side * (math.pi / 2.0) + fx = EAVE_HALF * math.sin(yaw) + fy = EAVE_HALF * math.cos(yaw) + if side % 2 == 0: + add_box( + bm, + (0.0, fy, EAVE_Z - fascia_h / 2.0), + (2.0 * EAVE_HALF + fascia_t, fascia_t, fascia_h), + WOOD_IDX, + ) + else: + add_box( + bm, + (fx, 0.0, EAVE_Z - fascia_h / 2.0), + (fascia_t, 2.0 * EAVE_HALF + fascia_t, fascia_h), + WOOD_IDX, + ) + + rope_top = beam_z - WINDLASS_R + rope_bot = BUCKET_Z + BUCKET_H / 2.0 + rope_h = rope_top - rope_bot + add_cylinder( + bm, + (0.0, 0.0, (rope_top + rope_bot) / 2.0), + ROPE_R, + rope_h, + 8, + WOOD_IDX, + ) + add_cylinder(bm, (0.0, 0.0, BUCKET_Z), BUCKET_R, BUCKET_H, 12, WOOD_IDX) + for hz in (-BUCKET_H * 0.28, BUCKET_H * 0.28): + add_cylinder( + bm, + (0.0, 0.0, BUCKET_Z + hz), + BUCKET_R + 0.008, + 0.018, + 12, + METAL_IDX, + ) + add_box( + bm, + (0.0, 0.0, BUCKET_Z + BUCKET_H / 2.0 + 0.04), + (BUCKET_R * 1.6, 0.014, 0.014), + METAL_IDX, + ) + add_box( + bm, + (-BUCKET_R * 0.72, 0.0, BUCKET_Z + BUCKET_H / 2.0 + 0.02), + (0.014, 0.014, 0.05), + METAL_IDX, + ) + add_box( + bm, + (BUCKET_R * 0.72, 0.0, BUCKET_Z + BUCKET_H / 2.0 + 0.02), + (0.014, 0.014, 0.05), + METAL_IDX, + ) + + pack_uvs(bm) + bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces)) + for face in bm.faces: + face.smooth = True + for edge in bm.edges: + edge.smooth = True + if edge.is_manifold and len(edge.link_faces) == 2: + if edge.calc_face_angle() > math.radians(35.0): + edge.smooth = False + me = bpy.data.meshes.new(name) + bm.to_mesh(me) + me.update() + finally: + bm.free() + obj = bpy.data.objects.new(name, me) + bpy.context.collection.objects.link(obj) + return obj + + +def principled(name, color, metallic, roughness): + mat = bpy.data.materials.new(name) + mat.use_nodes = True + bsdf = mat.node_tree.nodes["Principled BSDF"] + bsdf.inputs["Base Color"].default_value = color + bsdf.inputs["Metallic"].default_value = metallic + bsdf.inputs["Roughness"].default_value = roughness + return mat + + +def assign_slots(obj, stone, wood, metal): + obj.data.materials.clear() + obj.data.materials.append(stone) + obj.data.materials.append(wood) + obj.data.materials.append(metal) + + +def world_bbox(obj): + corners = [obj.matrix_world @ Vector(c) for c in obj.bound_box] + xs = [c.x for c in corners] + ys = [c.y for c in corners] + zs = [c.z for c in corners] + return (min(xs), min(ys), min(zs), max(xs), max(ys), max(zs)) + + +def uv_stats(mesh): + uv = mesh.uv_layers.active + if uv is None: + return 0.0, 0.0, 1.0, 1.0, 0, 1.0 + data = uv.data + us = [loop.uv[0] for loop in data] + vs = [loop.uv[1] for loop in data] + aabbs = [] + for poly in mesh.polygons: + pu = [data[i].uv[0] for i in poly.loop_indices] + pv = [data[i].uv[1] for i in poly.loop_indices] + aabbs.append((min(pu), min(pv), max(pu), max(pv))) + overlap = 0.0 + for i in range(len(aabbs)): + a = aabbs[i] + for j in range(i + 1, len(aabbs)): + b = aabbs[j] + x0 = max(a[0], b[0]) + y0 = max(a[1], b[1]) + x1 = min(a[2], b[2]) + y1 = min(a[3], b[3]) + overlap += max(0.0, x1 - x0) * max(0.0, y1 - y0) + return min(us), min(vs), max(us), max(vs), overlap, len(aabbs) + + +def make_lod(obj, name, ratio, skip_decimate): + mesh = obj.data.copy() + lod = bpy.data.objects.new(name, mesh) + lod.matrix_world = obj.matrix_world.copy() + bpy.context.scene.collection.objects.link(lod) + if not skip_decimate and 0.0 < ratio < 1.0: + mod = lod.modifiers.new("DecimateBudget", "DECIMATE") + mod.decimate_type = "COLLAPSE" + mod.ratio = ratio + return lod + + +def convex_hull_collider(obj, name): + # Duplicated from snippets/convex_hull_collider.py (not a package). + mesh = bpy.data.meshes.new(name) + bm = bmesh.new() + try: + bm.from_mesh(obj.data) + result = bmesh.ops.convex_hull(bm, input=list(bm.verts)) + interior = result.get("geom_interior") or [] + unused = result.get("geom_unused") or [] + if interior: + bmesh.ops.delete(bm, geom=interior, context="VERTS") + if unused: + bmesh.ops.delete(bm, geom=unused, context="VERTS") + bm.to_mesh(mesh) + mesh.update() + finally: + bm.free() + collider = bpy.data.objects.new(name, mesh) + bpy.context.collection.objects.link(collider) + collider.matrix_world = obj.matrix_world.copy() + return collider + + +def setup_bake_image(obj, target_mat, size=BAKE_RES): + # Adapted from snippets/setup_bake_target_image.py — do not replace slots. + if not obj.data.uv_layers: + return None, None + img = bpy.data.images.new("WellNrm", size, size, alpha=True, float_buffer=False) + img.colorspace_settings.name = "Non-Color" + nodes = target_mat.node_tree.nodes + tex = nodes.new("ShaderNodeTexImage") + tex.image = img + nodes.active = tex + tex.select = True + obj.active_material_index = STONE_IDX + return img, tex + + +def bake_normal(high, low): + # Duplicated from snippets/bake_normal_high_to_low.py (not a package). + scene = bpy.context.scene + scene.render.engine = "CYCLES" + scene.cycles.device = "CPU" + scene.cycles.samples = 1 + scene.cycles.use_denoising = False + for ob in bpy.context.view_layer.objects: + ob.select_set(False) + high.select_set(True) + low.select_set(True) + bpy.context.view_layer.objects.active = low + return bpy.ops.object.bake( + type="NORMAL", + use_selected_to_active=True, + cage_extrusion=CAGE_EXTRUSION, + use_cage=False, + normal_space="TANGENT", + margin=4, + margin_type="ADJACENT_FACES", + use_clear=True, + target="IMAGE_TEXTURES", + ) + + +def export_unity(path, objects): + # Duplicated from snippets/export_preset_unity.py (not a package). + for ob in bpy.context.view_layer.objects: + ob.select_set(False) + for ob in objects: + ob.select_set(True) + bpy.context.view_layer.objects.active = objects[0] + bpy.ops.export_scene.gltf( + filepath=path, + use_selection=True, + export_yup=True, + export_apply=True, + export_draco_mesh_compression_enable=False, + export_animations=False, + ) + + +def check(skip_decimate): + bpy.ops.wm.read_factory_settings(use_empty=True) + low = build_well_mesh("WellLow", bevel_offset=0.010, bevel_segments=2) + high = build_well_mesh("WellHigh", bevel_offset=0.010, bevel_segments=4) + stone = principled("WellStone", (0.40, 0.42, 0.46, 1.0), 0.0, 0.84) + wood = principled("WellWood", (0.48, 0.22, 0.07, 1.0), 0.0, 0.50) + metal = principled("WellMetal", (0.62, 0.58, 0.48, 1.0), 1.0, 0.25) + assign_slots(low, stone, wood, metal) + assign_slots(high, stone, wood, metal) + + if low.data is None or len(low.data.polygons) < 6: + return fail("well mesh did not build", 3), None, None, None, None, None + + base_tris = triangle_count(low.data) + mats = [s for s in low.data.materials if s is not None] + nmat = len(mats) + distinct_mats = len({id(s) for s in mats}) + u0, v0, u1, v1, overlap, nfaces = uv_stats(low.data) + bb = world_bbox(low) + size_x = bb[3] - bb[0] + size_y = bb[4] - bb[1] + size_z = bb[5] - bb[2] + + img, tex = setup_bake_image(low, stone) + if img is None: + return fail("well has no UV layer", 3), None, None, None, None, None + bake_result = bake_normal(high, low) + + lod1 = make_lod(low, "WellLOD1", LOD1_TARGET, skip_decimate) + lod2 = make_lod(low, "WellLOD2", LOD2_TARGET, skip_decimate) + bpy.context.view_layer.update() + lod1_tris = evaluated_triangle_count(lod1) + lod2_tris = evaluated_triangle_count(lod2) + r1 = lod1_tris / base_tris if base_tris else 0.0 + r2 = lod2_tris / base_tris if base_tris else 0.0 + + collider = convex_hull_collider(low, "WellCollider") + col_tris = triangle_count(collider.data) + + export_path = os.path.join( + tempfile.gettempdir(), + f"bdt_stone_well_{os.getpid()}.glb", + ) + if os.path.exists(export_path): + os.remove(export_path) + export_unity(export_path, [low, collider]) + export_size = os.path.getsize(export_path) if os.path.isfile(export_path) else 0 + + print( + f"blender={tuple(bpy.app.version)} skip_decimate={skip_decimate}" + ) + print( + f"measured base_tris={base_tris} lod1_tris={lod1_tris} " + f"lod2_tris={lod2_tris} r1={r1:.4f} r2={r2:.4f}" + ) + print( + f"measured nmat={nmat} uv=({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f}) " + f"overlap={overlap:.6f} nfaces={nfaces}" + ) + print( + f"measured bbox=({size_x:.4f},{size_y:.4f},{size_z:.4f}) " + f"outer={OUTER_SIZE} zmin={bb[2]:.4f}" + ) + print( + f"measured collider_tris={col_tris} bake={bake_result} " + f"bake_has_data={img.has_data} export_bytes={export_size}" + ) + + if not (BASE_TRIS_MIN <= base_tris <= BASE_TRIS_MAX): + return fail( + f"base tris {base_tris} not in [{BASE_TRIS_MIN}, {BASE_TRIS_MAX}]", + 4, + ), None, None, None, None, None + if nmat != MATERIAL_COUNT or distinct_mats != MATERIAL_COUNT: + return fail( + f"material slots {nmat} distinct {distinct_mats} != {MATERIAL_COUNT}", + 5, + ), None, None, None, None, None + if u0 < -UV_EPS or v0 < -UV_EPS or u1 > 1.0 + UV_EPS or v1 > 1.0 + UV_EPS: + return fail( + f"UVs outside 0..1: ({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f})", + 6, + ), None, None, None, None, None + if overlap > UV_OVERLAP_MAX: + return fail( + f"UV AABB overlap {overlap:.6f} > {UV_OVERLAP_MAX}", + 7, + ), None, None, None, None, None + if ( + abs(size_x - OUTER_SIZE[0]) > BBOX_TOL + or abs(size_y - OUTER_SIZE[1]) > BBOX_TOL + or abs(size_z - OUTER_SIZE[2]) > BBOX_TOL + ): + return fail( + f"bbox ({size_x:.4f},{size_y:.4f},{size_z:.4f}) " + f"off outer {OUTER_SIZE}", + 8, + ), None, None, None, None, None + if not (LOD1_RATIO_MIN <= r1 <= LOD1_RATIO_MAX): + return fail( + f"LOD1 ratio {r1:.4f} not in [{LOD1_RATIO_MIN}, {LOD1_RATIO_MAX}] " + "(--skip-decimate is the designed fail)", + 9, + ), None, None, None, None, None + if not (LOD2_RATIO_MIN <= r2 <= LOD2_RATIO_MAX): + return fail( + f"LOD2 ratio {r2:.4f} not in [{LOD2_RATIO_MIN}, {LOD2_RATIO_MAX}]", + 9, + ), None, None, None, None, None + if col_tris > COLLIDER_TRIS_MAX: + return fail( + f"collider tris {col_tris} > {COLLIDER_TRIS_MAX}", + 11, + ), None, None, None, None, None + if bake_result != {"FINISHED"} or not img.has_data: + return fail( + f"bake failed result={bake_result} has_data={img.has_data}", + 12, + ), None, None, None, None, None + if export_size <= 0: + return fail("export file missing or empty", 13), None, None, None, None, None + return 0, low, high, stone, tex, collider + + +def wire_normal(mat, tex): + nt = mat.node_tree + bsdf = nt.nodes["Principled BSDF"] + nrm = nt.nodes.new("ShaderNodeNormalMap") + nrm.inputs["Strength"].default_value = 1.0 + nt.links.new(tex.outputs["Color"], nrm.inputs["Color"]) + nt.links.new(nrm.outputs["Normal"], bsdf.inputs["Normal"]) + + +def render_still(low, stone, tex, path, engine): + scene = bpy.context.scene + wire_normal(stone, tex) + for ob in list(scene.objects): + if ob.type == "MESH" and ob != low: + ob.hide_render = True + ob.hide_viewport = True + + low.rotation_euler.z = math.radians(-28.0) + low.rotation_euler.x = math.radians(2.0) + + floor_me = bpy.data.meshes.new("Floor") + bm = bmesh.new() + try: + bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0) + bm.to_mesh(floor_me) + finally: + bm.free() + fmat = bpy.data.materials.new("Floor") + fmat.use_nodes = True + fb = fmat.node_tree.nodes["Principled BSDF"] + fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0) + fb.inputs["Roughness"].default_value = 0.7 + floor_me.materials.append(fmat) + floor = bpy.data.objects.new("Floor", floor_me) + scene.collection.objects.link(floor) + wall = bpy.data.objects.new("Wall", floor_me.copy()) + wall.location = (0.0, 8.5, 0.0) + wall.rotation_euler = (math.radians(90), 0.0, 0.0) + scene.collection.objects.link(wall) + + world = bpy.data.worlds.new("World") + world.use_nodes = True + world.node_tree.nodes["Background"].inputs["Color"].default_value = ( + 0.02, 0.021, 0.025, 1.0, + ) + scene.world = world + + def light(name, loc, energy, size, col, rot): + ld = bpy.data.lights.new(name, "AREA") + ld.energy = energy + ld.size = size + ld.color = col + ob = bpy.data.objects.new(name, ld) + ob.location = loc + ob.rotation_euler = tuple(math.radians(a) for a in rot) + scene.collection.objects.link(ob) + + light("Key", (-3.6, -5.0, 5.8), 680.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36)) + light("Fill", (5.0, -3.6, 2.6), 48.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50)) + light("Wedge", (2.4, 4.2, 4.1), 640.0, 5.5, (1.0, 0.70, 0.40), (-70, 0, 198)) + + cam_data = bpy.data.cameras.new("Cam") + cam_data.lens = 50.0 + cam = bpy.data.objects.new("Cam", cam_data) + cam.location = (3.10, -4.45, 2.12) + scene.collection.objects.link(cam) + aim = bpy.data.objects.new("Aim", None) + aim.location = (0.0, 0.0, OUTER_SIZE[2] / 2.0 + 0.04) + scene.collection.objects.link(aim) + con = cam.constraints.new("TRACK_TO") + con.target = aim + con.track_axis = "TRACK_NEGATIVE_Z" + con.up_axis = "UP_Y" + scene.camera = cam + + scene.render.engine = "CYCLES" if engine == "cycles" else eevee_engine_id() + if engine == "cycles": + scene.cycles.samples = 32 + scene.cycles.device = "CPU" + else: + try: + scene.eevee.taa_render_samples = 64 + except AttributeError: + pass + scene.render.resolution_x = 1280 + scene.render.resolution_y = 720 + scene.render.image_settings.file_format = ( + "WEBP" if path.lower().endswith(".webp") else "PNG" + ) + if path.lower().endswith(".webp"): + scene.render.image_settings.quality = 90 + scene.render.filepath = path + scene.view_settings.view_transform = "Standard" + + fcode = gallery_framing.check_framing( + scene, cam, hero=[low], elements=[low], stage=[floor, wall], + ) + if fcode: + return fcode + bpy.ops.render.render(write_still=True) + if not (os.path.exists(path) and os.path.getsize(path) > 0): + return fail("render produced no file", 14) + return 0 + + +def main(): + argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else [] + p = argparse.ArgumentParser() + p.add_argument("--output", default=None) + p.add_argument("--engine", default="eevee", choices=("eevee", "cycles")) + p.add_argument( + "--skip-decimate", + action="store_true", + help="falsification: skip the LOD DECIMATE stage", + ) + args = p.parse_args(argv) + + code, low, _high, stone, tex, _col = check(args.skip_decimate) + if code: + return code + if args.output: + rcode = render_still(low, stone, tex, os.path.abspath(args.output), args.engine) + if rcode: + return rcode + print(f"rendered still {args.output}") + print("stone-well OK") + return 0 + + +if __name__ == "__main__": + try: + sys.exit(main()) + except Exception as e: + traceback.print_exc() + print(f"FATAL: {e}", file=sys.stderr) + sys.exit(1) diff --git a/showcase/wooden-barrel/README.md b/showcase/wooden-barrel/README.md new file mode 100644 index 0000000..2a3534f --- /dev/null +++ b/showcase/wooden-barrel/README.md @@ -0,0 +1,73 @@ +# Wooden barrel + +A showcase piece, not an example. Procedural staved barrel (bulged staves, +four iron hoops, top and bottom heads) then the shipped pipeline: +unique-cell UVs, Cycles high-to-low normal bake, LOD chain, convex +collider, Unity glTF export. + +It asserts **budget conformance** of the generated result. It does not +witness an API contract. "It rendered without error" is not a check. + +**Composes** skills `mesh-editing-and-bmesh`, `bake-high-to-low`, +`depsgraph-and-evaluated-data`, `engine-export-presets`, and snippets +`bake_normal_high_to_low.py`, `setup_bake_target_image.py`, +`lod_chain.py` / `decimate_to_budget.py`, `convex_hull_collider.py`, +`export_preset_unity.py` (helpers copied, not imported as a package). + +## Budgets + +Declared as named constants; every gate **recomputes** from the mesh, +materials, UVs, evaluated LOD, collider, or export file. + +| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) | +| --- | --- | --- | +| Base triangles | 4200–4450 | 4312 / 4312 / 4312 | +| LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | +| LOD2 ratio | 0.10–0.35 of base | 0.2199 / 0.2199 / 0.2199 | +| Materials | exactly 2 distinct, ≥16 metal hoop faces | 2 slots, 88 hoop faces | +| UVs | in `0..1`, AABB overlap ≤ 1e-5 | in range, overlap 0 | +| Outer AABB | (0.719, 0.719, 0.880) m ± 0.01 | (0.7194, 0.7194, 0.8800), zmin 0 | +| Collider tris | ≤ 400 | 372 | +| Export | written, size > 0 | 327564 / 327564 / 327556 bytes | + +DECIMATE COLLAPSE triangle counts are **not** guaranteed identical across +series — the gate is a ratio band, not an exact count. This mesh happened +to match on 4.5.11 / 5.1.2 / 5.2.1. Bake pixels are stochastic; the gate +is `has_data` plus operator `FINISHED`, not byte-identity. Construction +uses no RNG. glTF byte size differs by a few bytes across series. + +`--skip-decimate` skips the LOD DECIMATE stage so LOD1 ratio is 1.0 and +exit 9 fires. That is the named budget the falsifier violates. + +## Run + +```bash +blender --background --python wooden_barrel.py -- +blender --background --python wooden_barrel.py -- --skip-decimate +blender --background --python wooden_barrel.py -- --output barrel.png +``` + +Smoke does not pass `--output` or `--skip-decimate`. + +## Exit codes + +File-local. `9` is a valid check code. `10` is reserved for +`gallery_framing.check_framing` on the `--output` path. + +| Code | Meaning | +| --- | --- | +| 0 | Success | +| 1 | Uncaught exception (FATAL wrapper) | +| 2 | argparse / usage | +| 3 | Mesh did not build / no UV layer | +| 4 | Base triangle count outside range | +| 5 | Material count ≠ 2 distinct slots, or hoop faces missing | +| 6 | UVs outside 0..1 | +| 7 | UV AABB overlap above tolerance | +| 8 | World AABB off declared outer size | +| 9 | LOD ratio band (`--skip-decimate` lands here) | +| 10 | Framing gate (render path only) | +| 11 | Collider triangle count above ceiling | +| 12 | Bake did not finish or image has no data | +| 13 | Export file missing or empty | +| 14 | `--output` produced no file | diff --git a/showcase/wooden-barrel/preview.webp b/showcase/wooden-barrel/preview.webp new file mode 100644 index 0000000..2f70c8e Binary files /dev/null and b/showcase/wooden-barrel/preview.webp differ diff --git a/showcase/wooden-barrel/wooden_barrel.py b/showcase/wooden-barrel/wooden_barrel.py new file mode 100644 index 0000000..6974703 --- /dev/null +++ b/showcase/wooden-barrel/wooden_barrel.py @@ -0,0 +1,685 @@ +"""Game-ready wooden barrel — a showcase piece, not an example. + +Asserts budget conformance of a procedural staved barrel after composing +shipped pipeline pieces: bmesh construction, UVs, two materials, high-to-low +normal bake, LOD chain, convex collider, Unity glTF export. + +Budgets are declared below and recomputed from the generated result. +They are not API-contract witnesses. ``--skip-decimate`` skips the LOD +DECIMATE stage so the LOD-ratio budget fails. + +No RNG. Construction is closed-form. DECIMATE COLLAPSE triangle counts +are not byte-identical across Blender versions — the LOD gate is a +ratio band, not an exact count. + + blender --background --python wooden_barrel.py -- + blender --background --python wooden_barrel.py -- --skip-decimate + blender --background --python wooden_barrel.py -- --output barrel.png +""" +import argparse +import math +import os +import sys +import tempfile +import traceback + +import bmesh +import bpy +from mathutils import Euler, Vector + +# Showcase lives at repo-root/showcase/, not under examples/. The framing +# helper is the repo's only shared import and lives next to the examples; +# resolve the repo root so we do not move gallery_framing.py. +_REPO = os.path.abspath( + os.path.join(os.path.dirname(os.path.abspath(__file__)), os.pardir, os.pardir) +) +sys.path.insert(0, os.path.join(_REPO, "examples")) +sys.dont_write_bytecode = True +import gallery_framing # noqa: E402 + +HEIGHT = 0.88 +R_END = 0.27 +R_MID = 0.36 +N_STAVES = 12 +STAVE_THICK = 0.030 +N_RINGS = 5 +STAVE_GAP = 0.05 +HOOP_ZS = (0.10, 0.28, 0.60, 0.78) +HOOP_H = 0.042 +HOOP_PAD = 0.014 +LID_T = 0.030 +BBOX_TOL = 0.01 +OUTER_SIZE = (0.719, 0.719, 0.880) + +BASE_TRIS_MIN = 4200 +BASE_TRIS_MAX = 4450 +LOD1_RATIO_MIN = 0.32 +LOD1_RATIO_MAX = 0.62 +LOD2_RATIO_MIN = 0.10 +LOD2_RATIO_MAX = 0.35 +LOD1_TARGET = 0.50 +LOD2_TARGET = 0.22 +MATERIAL_COUNT = 2 +UV_EPS = 1e-4 +UV_OVERLAP_MAX = 1e-5 +COLLIDER_TRIS_MAX = 400 +BAKE_RES = 256 +CAGE_EXTRUSION = 0.05 + +WOOD_IDX = 0 +METAL_IDX = 1 + + +def eevee_engine_id(): + return "BLENDER_EEVEE" if bpy.app.version >= (5, 0, 0) else "BLENDER_EEVEE_NEXT" + + +def fail(msg, code): + print(f"ERROR: {msg}", file=sys.stderr) + return code + + +def triangle_count(mesh): + mesh.calc_loop_triangles() + return len(mesh.loop_triangles) + + +def evaluated_triangle_count(obj): + # Duplicated from snippets/lod_chain.py / decimate_to_budget.py (not a package). + depsgraph = bpy.context.evaluated_depsgraph_get() + eval_obj = obj.evaluated_get(depsgraph) + eval_mesh = eval_obj.to_mesh() + try: + eval_mesh.calc_loop_triangles() + return len(eval_mesh.loop_triangles) + finally: + eval_obj.to_mesh_clear() + + +def radius_at(z): + return R_END + (R_MID - R_END) * math.sin(math.pi * z / HEIGHT) + + +def add_cone(bm, loc, radius1, radius2, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)): + geo = bmesh.ops.create_cone( + bm, + cap_ends=True, + cap_tris=False, + segments=segments, + radius1=radius1, + radius2=radius2, + depth=depth, + ) + verts = list(geo["verts"]) + rot = Euler(euler).to_matrix() + origin = Vector(loc) + for v in verts: + v.co = rot @ v.co + origin + bm.faces.ensure_lookup_table() + faces = {f for v in verts for f in v.link_faces} + for f in faces: + f.material_index = mat_idx + return verts + + +def add_cylinder(bm, loc, radius, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)): + return add_cone(bm, loc, radius, radius, depth, segments, mat_idx, euler=euler) + + +def pack_uvs(bm, margin=0.08): + uv = bm.loops.layers.uv.new("UVMap") + faces = list(bm.faces) + n = len(faces) + cols = max(1, math.ceil(math.sqrt(n))) + rows = max(1, math.ceil(n / cols)) + cell_w = 1.0 / cols + cell_h = 1.0 / rows + pad_u = margin * cell_w * 0.5 + pad_v = margin * cell_h * 0.5 + usable_w = cell_w - 2.0 * pad_u + usable_h = cell_h - 2.0 * pad_v + for i, face in enumerate(faces): + col = i % cols + row = i // cols + nrm = face.normal + ax = abs(nrm.x) + ay = abs(nrm.y) + az = abs(nrm.z) + coords = [] + for loop in face.loops: + co = loop.vert.co + if az >= ax and az >= ay: + coords.append((co.x, co.y)) + elif ax >= ay: + coords.append((co.y, co.z)) + else: + coords.append((co.x, co.z)) + xs = [c[0] for c in coords] + ys = [c[1] for c in coords] + minx, maxx = min(xs), max(xs) + miny, maxy = min(ys), max(ys) + dx = max(maxx - minx, 1e-8) + dy = max(maxy - miny, 1e-8) + origin_u = col * cell_w + pad_u + origin_v = row * cell_h + pad_v + for loop, (x, y) in zip(face.loops, coords): + loop[uv].uv = ( + origin_u + (x - minx) / dx * usable_w, + origin_v + (y - miny) / dy * usable_h, + ) + + +def build_barrel_mesh(name, bevel_offset, bevel_segments): + bm = bmesh.new() + stave_verts = [] + try: + zs = [HEIGHT * i / (N_RINGS - 1) for i in range(N_RINGS)] + for i in range(N_STAVES): + a0 = 2.0 * math.pi * i / N_STAVES + a1 = 2.0 * math.pi * (i + 1.0 - STAVE_GAP) / N_STAVES + outer = [] + inner = [] + for z in zs: + r = radius_at(z) + ov = ( + bm.verts.new((r * math.cos(a0), r * math.sin(a0), z)), + bm.verts.new((r * math.cos(a1), r * math.sin(a1), z)), + ) + ri = r - STAVE_THICK + iv = ( + bm.verts.new((ri * math.cos(a0), ri * math.sin(a0), z)), + bm.verts.new((ri * math.cos(a1), ri * math.sin(a1), z)), + ) + outer.append(ov) + inner.append(iv) + stave_verts.extend(ov) + stave_verts.extend(iv) + for k in range(N_RINGS - 1): + o0a, o0b = outer[k] + o1a, o1b = outer[k + 1] + i0a, i0b = inner[k] + i1a, i1b = inner[k + 1] + for vs in ( + (o0a, o1a, o1b, o0b), + (i0b, i1b, i1a, i0a), + (o0a, i0a, i1a, o1a), + (o0b, o1b, i1b, i0b), + ): + face = bm.faces.new(vs) + face.material_index = WOOD_IDX + top = bm.faces.new((outer[-1][0], outer[-1][1], inner[-1][1], inner[-1][0])) + top.material_index = WOOD_IDX + bot = bm.faces.new((outer[0][1], outer[0][0], inner[0][0], inner[0][1])) + bot.material_index = WOOD_IDX + + if bevel_offset > 0.0: + edges = list({e for v in stave_verts for e in v.link_edges}) + bmesh.ops.bevel( + bm, + geom=edges, + offset=bevel_offset, + segments=bevel_segments, + profile=0.5, + affect="EDGES", + clamp_overlap=True, + ) + + add_cylinder(bm, (0.0, 0.0, LID_T / 2.0), R_END - 0.012, LID_T, 16, WOOD_IDX) + add_cylinder( + bm, (0.0, 0.0, HEIGHT - LID_T / 2.0), R_END - 0.012, LID_T, 16, WOOD_IDX, + ) + hoop_faces = set() + for z in HOOP_ZS: + before = set(bm.faces) + add_cylinder( + bm, + (0.0, 0.0, z), + radius_at(z) + HOOP_PAD, + HOOP_H, + 20, + METAL_IDX, + ) + hoop_faces.update(set(bm.faces) - before) + + pack_uvs(bm) + bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces)) + for face in bm.faces: + face.smooth = True + for edge in bm.edges: + edge.smooth = True + if edge.is_manifold and len(edge.link_faces) == 2: + if edge.calc_face_angle() > math.radians(35.0): + edge.smooth = False + for f in hoop_faces: + if f.is_valid: + f.material_index = METAL_IDX + me = bpy.data.meshes.new(name) + bm.to_mesh(me) + me.update() + finally: + bm.free() + obj = bpy.data.objects.new(name, me) + bpy.context.collection.objects.link(obj) + return obj + + +def principled(name, color, metallic, roughness): + mat = bpy.data.materials.new(name) + mat.use_nodes = True + bsdf = mat.node_tree.nodes["Principled BSDF"] + bsdf.inputs["Base Color"].default_value = color + bsdf.inputs["Metallic"].default_value = metallic + bsdf.inputs["Roughness"].default_value = roughness + return mat + + +def assign_slots(obj, wood, metal): + # Do not materials.clear() — that resets polygon material_index to 0 + # on this Blender, which would drop hoop faces onto wood. + mats = obj.data.materials + if len(mats) == 0: + mats.append(wood) + mats.append(metal) + return + mats[0] = wood + if len(mats) == 1: + mats.append(metal) + else: + mats[1] = metal + + +def world_bbox(obj): + corners = [obj.matrix_world @ Vector(c) for c in obj.bound_box] + xs = [c.x for c in corners] + ys = [c.y for c in corners] + zs = [c.z for c in corners] + return (min(xs), min(ys), min(zs), max(xs), max(ys), max(zs)) + + +def uv_stats(mesh): + uv = mesh.uv_layers.active + if uv is None: + return 0.0, 0.0, 1.0, 1.0, 0, 1.0 + data = uv.data + us = [loop.uv[0] for loop in data] + vs = [loop.uv[1] for loop in data] + aabbs = [] + for poly in mesh.polygons: + pu = [data[i].uv[0] for i in poly.loop_indices] + pv = [data[i].uv[1] for i in poly.loop_indices] + aabbs.append((min(pu), min(pv), max(pu), max(pv))) + overlap = 0.0 + for i in range(len(aabbs)): + a = aabbs[i] + for j in range(i + 1, len(aabbs)): + b = aabbs[j] + x0 = max(a[0], b[0]) + y0 = max(a[1], b[1]) + x1 = min(a[2], b[2]) + y1 = min(a[3], b[3]) + overlap += max(0.0, x1 - x0) * max(0.0, y1 - y0) + return min(us), min(vs), max(us), max(vs), overlap, len(aabbs) + + +def make_lod(obj, name, ratio, skip_decimate): + mesh = obj.data.copy() + lod = bpy.data.objects.new(name, mesh) + lod.matrix_world = obj.matrix_world.copy() + bpy.context.scene.collection.objects.link(lod) + if not skip_decimate and 0.0 < ratio < 1.0: + mod = lod.modifiers.new("DecimateBudget", "DECIMATE") + mod.decimate_type = "COLLAPSE" + mod.ratio = ratio + return lod + + +def convex_hull_collider(obj, name): + # Duplicated from snippets/convex_hull_collider.py (not a package). + mesh = bpy.data.meshes.new(name) + bm = bmesh.new() + try: + bm.from_mesh(obj.data) + result = bmesh.ops.convex_hull(bm, input=list(bm.verts)) + interior = result.get("geom_interior") or [] + unused = result.get("geom_unused") or [] + if interior: + bmesh.ops.delete(bm, geom=interior, context="VERTS") + if unused: + bmesh.ops.delete(bm, geom=unused, context="VERTS") + bm.to_mesh(mesh) + mesh.update() + finally: + bm.free() + collider = bpy.data.objects.new(name, mesh) + bpy.context.collection.objects.link(collider) + collider.matrix_world = obj.matrix_world.copy() + return collider + + +def setup_bake_image(obj, target_mat, size=BAKE_RES): + # Adapted from snippets/setup_bake_target_image.py — do not replace slots. + if not obj.data.uv_layers: + return None, None + img = bpy.data.images.new("BarrelNrm", size, size, alpha=True, float_buffer=False) + img.colorspace_settings.name = "Non-Color" + nodes = target_mat.node_tree.nodes + tex = nodes.new("ShaderNodeTexImage") + tex.image = img + nodes.active = tex + tex.select = True + obj.active_material_index = WOOD_IDX + return img, tex + + +def bake_normal(high, low): + # Duplicated from snippets/bake_normal_high_to_low.py (not a package). + scene = bpy.context.scene + scene.render.engine = "CYCLES" + scene.cycles.device = "CPU" + scene.cycles.samples = 1 + scene.cycles.use_denoising = False + for ob in bpy.context.view_layer.objects: + ob.select_set(False) + high.select_set(True) + low.select_set(True) + bpy.context.view_layer.objects.active = low + return bpy.ops.object.bake( + type="NORMAL", + use_selected_to_active=True, + cage_extrusion=CAGE_EXTRUSION, + use_cage=False, + normal_space="TANGENT", + margin=4, + margin_type="ADJACENT_FACES", + use_clear=True, + target="IMAGE_TEXTURES", + ) + + +def export_unity(path, objects): + # Duplicated from snippets/export_preset_unity.py (not a package). + for ob in bpy.context.view_layer.objects: + ob.select_set(False) + for ob in objects: + ob.select_set(True) + bpy.context.view_layer.objects.active = objects[0] + bpy.ops.export_scene.gltf( + filepath=path, + use_selection=True, + export_yup=True, + export_apply=True, + export_draco_mesh_compression_enable=False, + export_animations=False, + ) + + +def check(skip_decimate): + bpy.ops.wm.read_factory_settings(use_empty=True) + low = build_barrel_mesh("BarrelLow", bevel_offset=0.006, bevel_segments=2) + high = build_barrel_mesh("BarrelHigh", bevel_offset=0.006, bevel_segments=4) + wood = principled("BarrelWood", (0.48, 0.22, 0.07, 1.0), 0.0, 0.50) + metal = principled("BarrelMetal", (0.62, 0.60, 0.56, 1.0), 1.0, 0.22) + assign_slots(low, wood, metal) + assign_slots(high, wood, metal) + + if low.data is None or len(low.data.polygons) < 6: + return fail("barrel mesh did not build", 3), None, None, None, None, None + + base_tris = triangle_count(low.data) + mats = [s for s in low.data.materials if s is not None] + nmat = len(mats) + distinct_mats = len({id(s) for s in mats}) + idx_counts = {} + for poly in low.data.polygons: + idx_counts[poly.material_index] = idx_counts.get(poly.material_index, 0) + 1 + print(f"measured mat_index_counts={idx_counts}") + u0, v0, u1, v1, overlap, nfaces = uv_stats(low.data) + bb = world_bbox(low) + size_x = bb[3] - bb[0] + size_y = bb[4] - bb[1] + size_z = bb[5] - bb[2] + + img, tex = setup_bake_image(low, wood) + if img is None: + return fail("barrel has no UV layer", 3), None, None, None, None, None + bake_result = bake_normal(high, low) + + lod1 = make_lod(low, "BarrelLOD1", LOD1_TARGET, skip_decimate) + lod2 = make_lod(low, "BarrelLOD2", LOD2_TARGET, skip_decimate) + bpy.context.view_layer.update() + lod1_tris = evaluated_triangle_count(lod1) + lod2_tris = evaluated_triangle_count(lod2) + r1 = lod1_tris / base_tris if base_tris else 0.0 + r2 = lod2_tris / base_tris if base_tris else 0.0 + + collider_src = build_barrel_mesh("BarrelColSrc", bevel_offset=0.0, bevel_segments=1) + collider = convex_hull_collider(collider_src, "BarrelCollider") + bpy.data.objects.remove(collider_src, do_unlink=True) + col_tris = triangle_count(collider.data) + + export_path = os.path.join( + tempfile.gettempdir(), + f"bdt_wooden_barrel_{os.getpid()}.glb", + ) + if os.path.exists(export_path): + os.remove(export_path) + export_unity(export_path, [low, collider]) + export_size = os.path.getsize(export_path) if os.path.isfile(export_path) else 0 + + print( + f"blender={tuple(bpy.app.version)} skip_decimate={skip_decimate}" + ) + print( + f"measured base_tris={base_tris} lod1_tris={lod1_tris} " + f"lod2_tris={lod2_tris} r1={r1:.4f} r2={r2:.4f}" + ) + print( + f"measured nmat={nmat} uv=({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f}) " + f"overlap={overlap:.6f} nfaces={nfaces}" + ) + print( + f"measured bbox=({size_x:.4f},{size_y:.4f},{size_z:.4f}) " + f"outer={OUTER_SIZE} zmin={bb[2]:.4f}" + ) + print( + f"measured collider_tris={col_tris} bake={bake_result} " + f"bake_has_data={img.has_data} export_bytes={export_size}" + ) + + if not (BASE_TRIS_MIN <= base_tris <= BASE_TRIS_MAX): + return fail( + f"base tris {base_tris} not in [{BASE_TRIS_MIN}, {BASE_TRIS_MAX}]", + 4, + ), None, None, None, None, None + if nmat != MATERIAL_COUNT or distinct_mats != MATERIAL_COUNT: + return fail( + f"material slots {nmat} distinct {distinct_mats} != {MATERIAL_COUNT}", + 5, + ), None, None, None, None, None + if idx_counts.get(METAL_IDX, 0) < 16: + return fail( + f"metal hoop faces {idx_counts.get(METAL_IDX, 0)} < 16", + 5, + ), None, None, None, None, None + if u0 < -UV_EPS or v0 < -UV_EPS or u1 > 1.0 + UV_EPS or v1 > 1.0 + UV_EPS: + return fail( + f"UVs outside 0..1: ({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f})", + 6, + ), None, None, None, None, None + if overlap > UV_OVERLAP_MAX: + return fail( + f"UV AABB overlap {overlap:.6f} > {UV_OVERLAP_MAX}", + 7, + ), None, None, None, None, None + if ( + abs(size_x - OUTER_SIZE[0]) > BBOX_TOL + or abs(size_y - OUTER_SIZE[1]) > BBOX_TOL + or abs(size_z - OUTER_SIZE[2]) > BBOX_TOL + ): + return fail( + f"bbox ({size_x:.4f},{size_y:.4f},{size_z:.4f}) " + f"off outer {OUTER_SIZE}", + 8, + ), None, None, None, None, None + if not (LOD1_RATIO_MIN <= r1 <= LOD1_RATIO_MAX): + return fail( + f"LOD1 ratio {r1:.4f} not in [{LOD1_RATIO_MIN}, {LOD1_RATIO_MAX}] " + "(--skip-decimate is the designed fail)", + 9, + ), None, None, None, None, None + if not (LOD2_RATIO_MIN <= r2 <= LOD2_RATIO_MAX): + return fail( + f"LOD2 ratio {r2:.4f} not in [{LOD2_RATIO_MIN}, {LOD2_RATIO_MAX}]", + 9, + ), None, None, None, None, None + if col_tris > COLLIDER_TRIS_MAX: + return fail( + f"collider tris {col_tris} > {COLLIDER_TRIS_MAX}", + 11, + ), None, None, None, None, None + if bake_result != {"FINISHED"} or not img.has_data: + return fail( + f"bake failed result={bake_result} has_data={img.has_data}", + 12, + ), None, None, None, None, None + if export_size <= 0: + return fail("export file missing or empty", 13), None, None, None, None, None + return 0, low, high, wood, tex, collider + + +def wire_normal(mat, tex): + nt = mat.node_tree + bsdf = nt.nodes["Principled BSDF"] + nrm = nt.nodes.new("ShaderNodeNormalMap") + nrm.inputs["Strength"].default_value = 1.0 + nt.links.new(tex.outputs["Color"], nrm.inputs["Color"]) + nt.links.new(nrm.outputs["Normal"], bsdf.inputs["Normal"]) + + +def render_still(low, wood, tex, path, engine): + scene = bpy.context.scene + wire_normal(wood, tex) + for ob in list(scene.objects): + if ob.type == "MESH" and ob != low: + ob.hide_render = True + ob.hide_viewport = True + + low.rotation_euler.z = math.radians(-32.0) + low.rotation_euler.x = math.radians(4.0) + + floor_me = bpy.data.meshes.new("Floor") + bm = bmesh.new() + try: + bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0) + bm.to_mesh(floor_me) + finally: + bm.free() + fmat = bpy.data.materials.new("Floor") + fmat.use_nodes = True + fb = fmat.node_tree.nodes["Principled BSDF"] + fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0) + fb.inputs["Roughness"].default_value = 0.7 + floor_me.materials.append(fmat) + floor = bpy.data.objects.new("Floor", floor_me) + scene.collection.objects.link(floor) + wall = bpy.data.objects.new("Wall", floor_me.copy()) + wall.location = (0.0, 8.5, 0.0) + wall.rotation_euler = (math.radians(90), 0.0, 0.0) + scene.collection.objects.link(wall) + + world = bpy.data.worlds.new("World") + world.use_nodes = True + world.node_tree.nodes["Background"].inputs["Color"].default_value = ( + 0.02, 0.021, 0.025, 1.0, + ) + scene.world = world + + def light(name, loc, energy, size, col, rot): + ld = bpy.data.lights.new(name, "AREA") + ld.energy = energy + ld.size = size + ld.color = col + ob = bpy.data.objects.new(name, ld) + ob.location = loc + ob.rotation_euler = tuple(math.radians(a) for a in rot) + scene.collection.objects.link(ob) + + light("Key", (-3.6, -5.0, 5.8), 680.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36)) + light("Fill", (5.0, -3.6, 2.6), 48.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50)) + light("Wedge", (2.4, 4.2, 4.1), 640.0, 5.5, (1.0, 0.70, 0.40), (-70, 0, 198)) + + cam_data = bpy.data.cameras.new("Cam") + cam_data.lens = 50.0 + cam = bpy.data.objects.new("Cam", cam_data) + cam.location = (1.68, -2.38, 1.38) + scene.collection.objects.link(cam) + aim = bpy.data.objects.new("Aim", None) + aim.location = (0.0, 0.0, HEIGHT / 2.0 + 0.02) + scene.collection.objects.link(aim) + con = cam.constraints.new("TRACK_TO") + con.target = aim + con.track_axis = "TRACK_NEGATIVE_Z" + con.up_axis = "UP_Y" + scene.camera = cam + + scene.render.engine = "CYCLES" if engine == "cycles" else eevee_engine_id() + if engine == "cycles": + scene.cycles.samples = 32 + scene.cycles.device = "CPU" + else: + try: + scene.eevee.taa_render_samples = 64 + except AttributeError: + pass + scene.render.resolution_x = 1280 + scene.render.resolution_y = 720 + scene.render.image_settings.file_format = ( + "WEBP" if path.lower().endswith(".webp") else "PNG" + ) + if path.lower().endswith(".webp"): + scene.render.image_settings.quality = 90 + scene.render.filepath = path + scene.view_settings.view_transform = "Standard" + + fcode = gallery_framing.check_framing( + scene, cam, hero=[low], elements=[low], stage=[floor, wall], + ) + if fcode: + return fcode + bpy.ops.render.render(write_still=True) + if not (os.path.exists(path) and os.path.getsize(path) > 0): + return fail("render produced no file", 14) + return 0 + + +def main(): + argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else [] + p = argparse.ArgumentParser() + p.add_argument("--output", default=None) + p.add_argument("--engine", default="eevee", choices=("eevee", "cycles")) + p.add_argument( + "--skip-decimate", + action="store_true", + help="falsification: skip the LOD DECIMATE stage", + ) + args = p.parse_args(argv) + + code, low, _high, wood, tex, _col = check(args.skip_decimate) + if code: + return code + if args.output: + rcode = render_still(low, wood, tex, os.path.abspath(args.output), args.engine) + if rcode: + return rcode + print(f"rendered still {args.output}") + print("wooden-barrel OK") + return 0 + + +if __name__ == "__main__": + try: + sys.exit(main()) + except Exception as e: + traceback.print_exc() + print(f"FATAL: {e}", file=sys.stderr) + sys.exit(1) diff --git a/tests/smoke/catalog.json b/tests/smoke/catalog.json index 8e94463..bc9124b 100644 --- a/tests/smoke/catalog.json +++ b/tests/smoke/catalog.json @@ -74,5 +74,7 @@ {"name": "gn-socket-rename", "script": "examples/gn-socket-rename/gn_socket_rename.py"}, {"name": "eval-mesh-datablock-name", "script": "examples/eval-mesh-datablock-name/eval_mesh_datablock_name.py"}, {"name": "mesh-automasking-settings", "script": "examples/mesh-automasking-settings/mesh_automasking_settings.py"}, - {"name": "shipping-crate", "script": "showcase/shipping-crate/shipping_crate.py"} + {"name": "shipping-crate", "script": "showcase/shipping-crate/shipping_crate.py"}, + {"name": "stone-well", "script": "showcase/stone-well/stone_well.py"}, + {"name": "wooden-barrel", "script": "showcase/wooden-barrel/wooden_barrel.py"} ]